Wireless Multicarrier Random Access Process

ABSTRACT

A Base station transmits a control command for transmission of a random access preamble on a secondary cell if the base station determines radio resources of the secondary cell are required for transmission of a portion of data and that the secondary cell requires a different uplink timing from currently activated and synchronized cells of the wireless device. The base station transmits at least one control packet for comprising transport format information and resource allocation information for transmission of a plurality of packets of the data to be transmitted on the secondary cell.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/748,583, filed Jan. 23, 2013, which claims the benefit of U.S.Provisional Application No. 61/590,366, filed Jan. 25, 2012, and U.S.Provisional Application No. 61/618,830, filed Apr. 1, 2012, and U.S.Provisional Application No. 61/661,329, filed Jun. 18, 2012, which arehereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present inventionare described herein with reference to the drawings, in which:

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention;

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers in a carrier group as per an aspect of anembodiment of the present invention;

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention;

FIG. 4 is a block diagram of a base station and a wireless device as peran aspect of an embodiment of the present invention;

FIG. 5 is a block diagram depicting a system for transmitting datatraffic over an OFDM radio system as per an aspect of an embodiment ofthe present invention;

FIG. 6 is a diagram depicting uplink transmission timing of one or morecells in a first timing advance group (TAG) and a second TAG as per anaspect of an embodiment of the present invention;

FIG. 7 is an example message flow in a random access process in asecondary TAG as per an aspect of an embodiment of the presentinvention;

FIG. 8 shows example TAG configurations as per an aspect of anembodiment of the present invention;

FIG. 9 is an example physical random access channel (PRACH)configuration in a primary TAG (pTAG) and a secondary TAG (sTAG) as peran aspect of an embodiment of the present invention;

FIG. 10 is an example flow diagram illustrating base station signalingto schedule packets on a secondary cell as per an aspect of anembodiment of the present invention;

FIG. 11 is an example flow diagram illustrating base station signalingto schedule packets on a secondary cell as per an aspect of anembodiment of the present invention;

FIG. 12 is an example flow diagram illustrating signaling mechanism toconfigure a plurality of cells and a plurality of cell groups as per anaspect of an embodiment of the present invention;

FIG. 13 is an example flow diagram illustrating a signaling mechanism toconfigure a plurality of cells and a plurality of cell groups as per anaspect of an embodiment of the present invention;

FIG. 14 is an example flow diagram illustrating a signaling mechanism toconfigure pathloss reference for secondary cells in a plurality of cellgroups as per an aspect of an embodiment of the present invention; and

FIG. 15 is an example flow diagram illustrating a signaling mechanism toconfigure pathloss reference for secondary cells in a plurality of cellgroups as per an aspect of an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present invention enable operation ofmultiple timing advance groups. Embodiments of the technology disclosedherein may be employed in the technical field of multicarriercommunication systems. More particularly, the embodiments of thetechnology disclosed herein may relate to operation of multiple timingadvance groups.

Example embodiments of the invention may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CDMA (codedivision multiple access), OFDM (orthogonal frequency divisionmultiplexing), TDMA (time division multiple access), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement QAM (quadrature amplitudemodulation) using BPSK (binary phase shift keying), QPSK (quadraturephase shift keying), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physicalradio transmission may be enhanced by dynamically or semi-dynamicallychanging the modulation and coding scheme depending on transmissionrequirements and radio conditions.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention. As illustrated in thisexample, arrow(s) in the diagram may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, SC-OFDM (single carrier-OFDM) technology, or the like.For example, arrow 101 shows a subcarrier transmitting informationsymbols. FIG. 1 is for illustration purposes, and a typical multicarrierOFDM system may include more subcarriers in a carrier. For example, thenumber of subcarriers in a carrier may be in the range of 10 to 10,000subcarriers. FIG. 1 shows two guard bands 106 and 107 in a transmissionband. As illustrated in FIG. 1, guard band 106 is between subcarriers103 and subcarriers 104. The example set of subcarriers A 102 includessubcarriers 103 and subcarriers 104. FIG. 1 also illustrates an exampleset of subcarriers B 105. As illustrated, there is no guard band betweenany two subcarriers in the example set of subcarriers B 105. Carriers ina multicarrier OFDM communication system may be contiguous carriers,non-contiguous carriers, or a combination of both contiguous andnon-contiguous carriers.

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentinvention. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 10 carriers. Carrier A 204and carrier B 205 may have the same or different timing structures.Although FIG. 2 shows two synchronized carriers, carrier A 204 andcarrier B 205 may or may not be synchronized with each other. Differentradio frame structures may be supported for FDD (frequency divisionduplex) and TDD (time division duplex) duplex mechanisms. FIG. 2 showsan example FDD frame timing. Downlink and uplink transmissions may beorganized into radio frames 201. In this example, radio frame durationis 10 msec. Other frame durations, for example, in the range of 1 to 100msec may also be supported. In this example, each 10 ms radio frame 201may be divided into ten equally sized sub-frames 202. Other subframedurations such as including 0.5 msec, 1 msec, 2 msec, and 5 msec mayalso be supported. Sub-frame(s) may consist of two or more slots 206.For the example of FDD, 10 subframes may be available for downlinktransmission and 10 subframes may be available for uplink transmissionsin each 10 ms interval. Uplink and downlink transmissions may beseparated in the frequency domain. Slot(s) may include a plurality ofOFDM symbols 203. The number of OFDM symbols 203 in a slot 206 maydepend on the cyclic prefix length and subcarrier spacing.

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention. The resource grid structure intime 304 and frequency 305 is illustrated in FIG. 3. The quantity ofdownlink subcarriers or resource blocks (RB) (in this example 6 to 100RBs) may depend, at least in part, on the downlink transmissionbandwidth 306 configured in the cell. The smallest radio resource unitmay be called a resource element (e.g. 301). Resource elements may begrouped into resource blocks (e.g. 302). Resource blocks may be groupedinto larger radio resources called Resource Block Groups (RBG) (e.g.303). The transmitted signal in slot 206 may be described by one orseveral resource grids of a plurality of subcarriers and a plurality ofOFDM symbols. Resource blocks may be used to describe the mapping ofcertain physical channels to resource elements. Other pre-definedgroupings of physical resource elements may be implemented in the systemdepending on the radio technology. For example, 24 subcarriers may begrouped as a radio block for a duration of 5 msec. In an illustrativeexample, a resource block may correspond to one slot in the time domainand 180 kHz in the frequency domain (for 15 KHz subcarrier bandwidth and12 subcarriers).

According to some embodiments, a radio resource framework using OFDMtechnology may be employed. Alternative embodiments may be implementedemploying other radio technologies. Example transmission mechanismsinclude, but are not limited to: CDMA, OFDM, TDMA, Wavelet technologies,and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, andOFDM/CDMA may also be employed.

FIG. 4 is an example block diagram of a base station 401 and a wirelessdevice 406, as per an aspect of an embodiment of the present invention.A communication network 400 may include at least one base station 401and at least one wireless device 406. The base station 401 may includeat least one communication interface 402, at least one processor 403,and at least one set of program code instructions 405 stored innon-transitory memory 404 and executable by the at least one processor403. The wireless device 406 may include at least one communicationinterface 407, at least one processor 408, and at least one set ofprogram code instructions 410 stored in non-transitory memory 409 andexecutable by the at least one processor 408. Communication interface402 in base station 401 may be configured to engage in communicationwith communication interface 407 in wireless device 406 via acommunication path that includes at least one wireless link 411.Wireless link 411 may be a bi-directional link. Communication interface407 in wireless device 406 may also be configured to engage in acommunication with communication interface 402 in base station 401. Basestation 401 and wireless device 406 may be configured to send andreceive data over wireless link 411 using multiple frequency carriers.According to some of the various aspects of embodiments, transceiver(s)may be employed. A transceiver is a device that includes both atransmitter and receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in communicationinterface 402, 407 and wireless link 411 are illustrated are FIG. 1,FIG. 2, and FIG. 3. and associated text.

FIG. 5 is a block diagram depicting a system 500 for transmitting datatraffic generated by a wireless device 502 to a server 508 over amulticarrier OFDM radio according to one aspect of the illustrativeembodiments. The system 500 may include a Wireless CellularNetwork/Internet Network 507, which may function to provide connectivitybetween one or more wireless devices 502 (e.g., a cell phone, PDA(personal digital assistant), other wirelessly-equipped device, and/orthe like), one or more servers 508 (e.g. multimedia server, applicationservers, email servers, or database servers) and/or the like.

It should be understood, however, that this and other arrangementsdescribed herein are set forth for purposes of example only. As such,those skilled in the art will appreciate that other arrangements andother elements (e.g., machines, interfaces, functions, orders offunctions, etc.) may be used instead, some elements may be added, andsome elements may be omitted altogether. Further, as in mosttelecommunications applications, those skilled in the art willappreciate that many of the elements described herein are functionalentities that may be implemented as discrete or distributed componentsor in conjunction with other components, and in any suitable combinationand location. Still further, various functions described herein as beingperformed by one or more entities may be carried out by hardware,firmware and/or software logic in combination with hardware. Forinstance, various functions may be carried out by a processor executinga set of machine language instructions stored in memory.

As shown, the access network may include a plurality of base stations503 . . . 504. Base station 503 . . . 504 of the access network mayfunction to transmit and receive RF (radio frequency) radiation 505 . .. 506 at one or more carrier frequencies, and the RF radiation mayprovide one or more air interfaces over which the wireless device 502may communicate with the base stations 503 . . . 504. The user 501 mayuse the wireless device (or UE: user equipment) to receive data traffic,such as one or more multimedia files, data files, pictures, video files,or voice mails, etc. The wireless device 502 may include applicationssuch as web email, email applications, upload and ftp applications, MMS(multimedia messaging system) applications, or file sharingapplications. In another example embodiment, the wireless device 502 mayautomatically send traffic to a server 508 without direct involvement ofa user. For example, consider a wireless camera with automatic uploadfeature, or a video camera uploading videos to the remote server 508, ora personal computer equipped with an application transmitting traffic toa remote server.

One or more base stations 503 . . . 504 may define a correspondingwireless coverage area. The RF radiation 505 . . . 506 of the basestations 503 . . . 504 may carry communications between the WirelessCellular Network/Internet Network 507 and access device 502 according toany of a variety of protocols. For example, RF radiation 505 . . . 506may carry communications according to WiMAX (Worldwide Interoperabilityfor Microwave Access e.g., IEEE 802.16), LTE (long term evolution),microwave, satellite, MMDS (Multichannel Multipoint DistributionService), Wi-Fi (e.g., IEEE 802.11), Bluetooth, infrared, and otherprotocols now known or later developed. The communication between thewireless device 502 and the server 508 may be enabled by any networkingand transport technology for example TCP/IP (transport controlprotocol/Internet protocol), RTP (real time protocol), RTCP (real timecontrol protocol), HTTP (Hypertext Transfer Protocol) or any othernetworking protocol.

According to some of the various aspects of embodiments, an LTE networkmay include many base stations, providing a user plane (PDCP: packetdata convergence protocol/RLC: radio link control/MAC: media accesscontrol/PHY: physical) and control plane (RRC: radio resource control)protocol terminations towards the wireless device. The base station(s)may be interconnected with other base station(s) by means of an X2interface. The base stations may also be connected by means of an S1interface to an EPC (Evolved Packet Core). For example, the basestations may be interconnected to the MME (Mobility Management Entity)by means of the S1-MME interface and to the Serving Gateway (S-GW) bymeans of the S1-U interface. The S1 interface may support a many-to-manyrelation between MMEs/Serving Gateways and base stations. A base stationmay include many sectors for example: 1, 2, 3, 4, or 6 sectors. A basestation may include many cells, for example, ranging from 1 to 50 cellsor more. A cell may be categorized, for example, as a primary cell orsecondary cell. When carrier aggregation is configured, a wirelessdevice may have one RRC connection with the network. At RRC connectionestablishment/re-establishment/handover, one serving cell may providethe NAS (non-access stratum) mobility information (e.g. TAI-trackingarea identifier), and at RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, the carriercorresponding to the PCell may be the Downlink Primary Component Carrier(DL PCC), while in the uplink, it may be the Uplink Primary ComponentCarrier (UL PCC). Depending on wireless device capabilities, SecondaryCells (SCells) may be configured to form together with the PCell a setof serving cells. In the downlink, the carrier corresponding to an SCellmay be a Downlink Secondary Component Carrier (DL SCC), while in theuplink, it may be an Uplink Secondary Component Carrier (UL SCC). AnSCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,is assigned a physical cell ID and a cell index. A carrier (downlink oruplink) belongs to only one cell, the cell ID or Cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the specification, cell ID may be equallyreferred to a carrier ID, and cell index may be referred to carrierindex. In implementation, the physical cell ID or cell index may beassigned to a cell. Cell ID may be determined using the synchronizationsignal transmitted on a downlink carrier. Cell index may be determinedusing RRC messages. For example, when the specification refers to afirst physical cell ID for a first downlink carrier, it may mean thefirst physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the specification indicates that a first carrier is activated, itequally means that the cell comprising the first carrier is activated.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in wireless device, base station, radio environment, network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, traffic load, initial systemset up, packet sizes, traffic characteristics, a combination of theabove, and/or the like. When the one or more criteria are met, theexample embodiments may be applied. Therefore, it may be possible toimplement example embodiments that selectively implement disclosedprotocols.

Example embodiments of the invention may enable operation of multipletiming advance groups. Other example embodiments may comprise anon-transitory tangible computer readable media comprising instructionsexecutable by one or more processors to cause operation of multipletiming advance groups. Yet other example embodiments may comprise anarticle of manufacture that comprises a non-transitory tangible computerreadable machine-accessible medium having instructions encoded thereonfor enabling programmable hardware to cause a device (e.g. wirelesscommunicator, UE, base station, etc.) to enable operation of multipletiming advance groups. The device may include processors, memory,interfaces, and/or the like. Other example embodiments may comprisecommunication networks comprising devices such as base stations,wireless devices (or user equipment: UE), servers, switches, antennas,and/or the like.

According to some of the various aspects of embodiments, serving cellshaving an uplink to which the same time alignment (TA) applies may begrouped in a TA group (TAG). Serving cells in one TAG may use the sametiming reference. For a given TAG, a user equipment (UE) may use onedownlink carrier as the timing reference at a given time. The UE may usea downlink carrier in a TAG as the timing reference for that TAG. For agiven TAG, a UE may synchronize uplink subframe and frame transmissiontiming of the uplink carriers belonging to the same TAG. According tosome of the various aspects of embodiments, serving cells having anuplink to which the same TA applies may correspond to the serving cellshosted by the same receiver. A TA group may comprise at least oneserving cell with a configured uplink. A UE supporting multiple TAs maysupport two or more TA groups. One TA group may contain the PCell andmay be called a primary TAG (pTAG). In a multiple TAG configuration, atleast one TA group may not contain the PCell and may be called asecondary TAG (sTAG). Carriers within the same TA group may use the sameTA value and the same timing reference. In this disclosure, timingadvance group, time alignment group, and cell group have the samemeaning. Further, time alignment command and timing advance command havethe same meaning.

FIG. 6 is a diagram depicting uplink transmission timing of one or morecells in a first timing advance group (TAG1) and a second TAG (TAG2) asper an aspect of an embodiment of the present invention. TAG1 mayinclude one or more cells, TAG2 may also include one or more cells. TAGtiming difference in FIG. 6 may be the difference in UE uplinktransmission timing for uplink carriers in TAG1 and TAG2. The timingdifference may range between, for example, sub micro-seconds to about 3omicro-seconds.

FIG. 8 shows example TAG configurations as per an aspect of anembodiment of the present invention. In Example 1, pTAG include PCell,and sTAG includes SCell1. In Example 2, pTAG includes PCell and SCell1,and sTAG includes SCell2 and SCell3. In Example 3, pTAG includes PCelland SCell1, and sTAG1 includes SCell2 and SCell3, and sTAG2 includesSCell4. Up to four TAGs may be supported and other example TAGconfigurations may also be provided. In many examples of thisdisclosure, example mechanisms are described for a pTAG and an sTAG. Theoperation with one example sTAG is described, and the same operation maybe applicable to other sTAGs. The example mechanisms may be applied toconfigurations with multiple sTAGs.

According to some of the various aspects of embodiments, TA maintenance,pathloss reference handling and the timing reference for pTAG may followLTE release 10 principles. The UE may need to measure downlink pathlossto calculate the uplink transmit power. The pathloss reference may beused for uplink power control and/or transmission of random accesspreamble(s). A UE may measure downlink pathloss using the signalsreceived on the pathloss reference cell. The pathloss reference downlinkcell and the corresponding uplink cell may be configured to be in thesame frequency band due to the required accuracy of pathloss estimation.For SCell(s) in a pTAG, the choice of pathloss reference for cells maybe selected from and be limited to the following two options: a) thedownlink SCell linked to an uplink SCell using the system informationblock 2 (SIB2), and b) the downlink pCell. The pathloss reference forSCells in pTAG may be configurable using RRC message(s) as a part ofSCell initial configuration and/or reconfiguration. According to some ofthe various aspects of embodiments, PhysicalConfigDedicatedSCellinformation element (IE) of an SCell configuration may include thepathloss reference SCell (downlink carrier) for an SCell in pTAG.

The downlink SCell linked to an uplink SCell using the systeminformation block 2 (SIB2) may be referred to as the SIB2 linkeddownlink of the SCell. Different TAGs may operate in different bands. Inanother example, the signals in different TAGs may travel throughdifferent repeaters, or the signal of one SCell in an sTAG may travelthrough a repeater while the signal of another TAG may not go throughthe repeater. Having flexibility in SCell pathloss referenceconfiguration for SCells belonging to an sTAG may result in pathlossestimation errors due to mobility of wireless device. The wirelessdevice may autonomously change a timing reference SCell in an sTAG, butchanging pathloss reference autonomously may result in confusion in theserving eNB, specially that different cells may have different transmitpower. Therefore, both eNB configuration flexibility and autonomous UEpathloss selection for an SCell in sTAG may result in errors in pathlossestimation. For an uplink carrier in an sTAG, the pathloss reference maybe only configurable to the downlink SCell linked to an uplink SCellusing the system information block 2 (SIB2) of the SCell. No otherdownlink carrier may be configured as the pathloss reference for anSCell in an sTAG. This configuration may introduce accuracy in pathlossestimation.

According to some of the various aspects of embodiments, a UE maysuccessfully complete a random access procedure from the reception of arandom access response (RAR) message within the random access (RA)response window using a random access radio network temporary identifier(RA-RNTI). The UE may decode scheduling information for uplinktransmission in the PDCCH common search space (CSS) with RA-RNTI.According to some of the various aspects of embodiments, in addition tothe time alignment command (TAC) field, RAR for a PCell and/or SCell maycontain at least one of the following: a Random Access PreambleIdentifier (RAPID), a UL grant, a Temporary C-RNTI, a Backoff Indicator(BI), and/or the like. RAPID may be used to confirm the associationbetween RAR and the transmitted preamble. The UL grant may be employedfor uplink transmission on the cell that the preamble was transmitted.Temporary C-RNTI may be used for contention resolution in case ofcontention based random access (CBRA). A backoff Indicator (BI) may beused in case of collisions and/or high load on PRACH.

To obtain initial uplink (UL) time alignment for an sTAG, eNB mayinitiate an RA procedure. In an sTAG, a UE may use one of any activatedSCells from this sTAG as a timing reference cell. In an exampleembodiment, the timing reference for SCells in an sTAG may be the SIB2linked downlink of the SCell on which the preamble for the latest RAprocedure was sent. There may be one timing reference and one timealignment timer (TAT) per TA group. TAT for TAGs may be configured withdifferent values. When the TAT associated with the pTAG expires: allTATs may be considered as expired, the UE may flush all HARQ buffers ofall serving cells, the UE may clear any configured downlinkassignment/uplink grants, and the RRC in the UE may release PUCCH/SRSfor all configured serving cells. When the pTAG TAT is not running, ansTAG TAT may not be running. When the TAT associated with sTAG expires:a) SRS transmissions may be stopped on the corresponding SCells, b) SRSRRC configuration may be released, c) CSI reporting configuration forthe corresponding SCells may be maintained, and/or d) the MAC in the UEmay flush the uplink HARQ buffers of the corresponding SCells.

Upon deactivation of the last SCell in an sTAG, the UE may not stop TATof the sTAG. In an implementation, upon removal of the last SCell in ansTAG, TAT of the TA group may not be running. RA procedures in parallelmay not be supported for a UE. If a new RA procedure is requested(either by UE or network) while another RA procedure is already ongoing,it may be up to the UE implementation whether to continue with theongoing procedure or start with the new procedure. The eNB may initiatethe RA procedure via a PDCCH order for an activated SCell. This PDCCHorder may be sent on the scheduling cell of this SCell. When crosscarrier scheduling is configured for a cell, the scheduling cell may bedifferent than the cell that is employed for preamble transmission, andthe PDCCH order may include the SCell index. At least a non-contentionbased RA procedure may be supported for SCell(s) assigned to sTAG(s).Upon new UL data arrival, the UE may not trigger an RA procedure on anSCell. PDCCH order for preamble transmission may be sent on a differentserving cell than the SCell in which the preamble is sent. TA groupingmay be performed without requiring any additional UE assistedinformation.

FIG. 7 is an example message flow in a random access process in asecondary TAG as per an aspect of an embodiment of the presentinvention. eNB transmits an activation command 600 to activate an SCell.A preamble 602 (Msg1) may be sent by a UE in response to the PDCCH order601 on an SCell belonging to an sTAG. In an example embodiment, preambletransmission for SCells may be controlled by the network using PDCCHformat 1A. Msg2 message 603 (RAR: random access response) in response tothe preamble transmission on SCell may be addressed to RA-CRNTI in PCellcommon search space (CSS). Uplink packets 604 may be transmitted on theSCell, in which the preamble was transmitted.

According to some of the various aspects of embodiments, initial timingalignment may be achieved through a random access procedure. This mayinvolve the UE transmitting a random access preamble and the eNBresponding to an initial TA command NTA (amount of time alignment)within the random access response window. The start of the random accesspreamble may be aligned with the start of the corresponding uplinksubframe at the UE assuming NTA=0. The eNB may estimate the uplinktiming from the random access preamble transmitted by the UE. The TAcommand may be derived by the eNB based on the estimation of thedifference between the desired UL timing and the actual UL timing. TheUE may determine the initial uplink transmission timing relative to thecorresponding downlink of the sTAG on which the preamble is transmitted.

PDCCH order may be used to trigger RACH for an activated SCell. For anewly configured SCell or a configured but deactivated SCell, eNB mayneed to firstly activate the corresponding SCell and then trigger a RAon it. In an example embodiment, with no retransmission of anactivation/deactivation command, activation of an SCell may need atleast 8 ms, which may be an extra delay for UE to acquire the valid TAvalue on an SCell compared to the procedure on an already activatedSCell. For a newly configured SCell or a deactivated SCell, 8 ms may berequired for SCell activation, and at least 6 ms may be required forpreamble transmission, and at least 4 ms may be required to receive therandom access response. At least 18 ms may be required for a UE to get avalid TA. The possible delay caused by retransmission or otherconfigured parameters may need to be considered (e.g. the possibleretransmission of an activation/deactivation command, and/or the timegap between when a RA is triggered and when a preamble is transmitted(equal or larger than 6 ms)). The RAR may be transmitted within the RARwindow (for example, 2 ms, 10 ms, 50 ms), and possible retransmission ofthe preamble may be considered. The delay for such a case may be morethan 20 ms or even 30 ms if retransmissions are considered.

A base station may communicate with a mix of wireless devices. Wirelessdevices may support multiple technologies, or multiple releases of thesame technology, have some specific capability depending on the wirelessdevice category and/or capability. A base station may comprise multiplesectors. When this disclosure refers to a base station communicatingwith a plurality of wireless devices, this disclosure may refer to asubset of the total wireless devices in the coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE release with a given capability and in a given sector of thebase station. The plurality of wireless devices in this disclosure mayrefer to a selected plurality of wireless devices, and/or a subset oftotal wireless devices in the coverage area, which perform according tothe disclosed methods, and/or the like. There may be many wirelessdevices in the coverage area that may not comply with the disclosedmethods, for example, because those wireless devices perform based onolder releases of LTE technology. A time alignment command MAC controlelement may be a unicast MAC command transmitted to a wireless device. Awireless device may receive its own time alignment commands.

According to some of the various aspects of various embodiments, thebase station or wireless device may group cells into a plurality of cellgroups. The term “cell group” may refer to a timing advance group (TAG)or a timing alignment group or a time alignment group. A cell group mayinclude at least one cell. A MAC TA command may correspond to a TAG. Agroup may explicitly or implicitly be identified by a TAG index. Cellsin the same band may belong to the same cell group. A first cell's frametiming may be tied to a second cell's frame timing in a TAG. When a timealignment command is received for the second cell, the frame timing ofboth first cell and second cell may be adjusted. Base station(s) mayprovide TAG configuration information to the wireless device(s) by RRCconfiguration message(s).

According to some of the various aspects of some embodiments, the numberof time alignment commands transmitted by the base station to a wirelessdevice in a given period may depend, at least in part, on manyparameters including at least one of: a) the speed that the wirelessdevice moves in the coverage area, b) the direction that the wirelessdevice moves in the coverage area, c) the coverage radius, and/or d) thenumber of active wireless devices in the coverage area. A base stationmay transmit at least two types of time alignment commands. A first typecommand may be transmitted to a first category of wireless devices. Thefirst category may include devices compatible with at least release 8,9, or 10 of the LTE standard. A second type command may be transmittedto a second category of devices. The second category may include deviceswith multi-time alignment group (MTG) capability and compatible withrelease 11 or beyond of the LTE standard. The time alignment may betransmitted to wireless devices that are in connected mode and areapplicable to active cells.

A UE may transmit a Scheduling Request (SR) and/or a buffer statusreport (BSR) due to uplink data arrival in the UE. A UE may transmit ascheduling request on PUCCH when the UE has data for uplink transmissionand UE do not have uplink grants for transmission of a buffer statusreport. The UE may receive uplink grant in response to a SR. A basestation scheduler may also provide an uplink grant to a UE for someother reasons, for example, based on a previous BSR. The UE may transmita MAC BSR in the uplink resources identified in an uplink grant toinform the base station about the size of the uplink transmissionbuffer(s). A UE BSR may be transmitted in an uplink resource identifiedin a received uplink grant. BSR indicates the amount of data in one ormore logical channel buffers. Base station may determine the radioresources required for the UE in the uplink employing the received BSRand other parameters, e.g. link quality, interference, UE category,and/or the like. If the base station determines that radio resources ofa first SCell which is uplink unsynchronized is required (the SCell maybe in-active or may not be even configured yet), the base station maytrigger an sTAG sync process to uplink synchronize the sTAG and thefirst SCell associated with the sTAG. The SCell should be in configured(e.g. using RRC messages) and be in active state (e.g. using MACactivate commands). An SCell is considered out-of-sync if it belongs toor will belong to (after RRC configuration) to an out-of-sync sTAG.

The sTAG sync process may also selectively be started by the basestation if a GBR bit rate bearer with required uplink resources has beenestablished. The Base station may determine the radio resources requiredfor the UE in the uplink employing the received bit rate, QoS andpriority requirements of the GBR bearer and other parameters, e.g. linkquality, interference, UE category, and/or the like. If the base stationdetermines that radio resources of a first SCell which is uplinkunsynchronized is required (the SCell may be in-active or may not beeven configured yet), the base station may trigger an sTAG sync processto uplink synchronize the sTAG and the first SCell associated with thesTAG. The SCell should be in configured (e.g. using RRC messages) and bein active state (e.g. using MAC activate commands) before uplinktransmission starts.

eNB may select to synchronize the sTAG and then activate/configure theSCell. eNB may select to first configure/activate SCell and then touplink synchronize it. For example, if an SCell is added and assigned toa synchronized sTAG, it will be synchronize upon its(re)configuration/addition. In another example, the SCell may beconfigured, then the sTAG may be synchronized using another SCell in thesTAG, and then the SCell may be activated. In another example, the SCellmay be configured/activated, and then sTAG synchronization may start.Different embodiments with different orders in tasks may be implemented.Random access process for an SCell can only be initiated on configuredand active SCells assigned to an sTAG.

In an example embodiment, in the sTAG sync process the base station maytrigger random access preamble transmission on an SCell of the sTAG thatthe SCell belongs, or on the first SCell in which its uplink resourcesare required. In this example, the first SCell belongs to an sTAG whichis uplink out-of-sync. In response to receiving a BSR and/or GBR bearerestablishment, the eNB may, selectively and depending on a plurality ofcriteria, transmit a PDCCH order to the UE and may cause the UE to starta RA procedure on an SCell in the sTAG (in case of carrier aggregation).A PDCCH order may be triggered by the BSR reception due to the UL dataarrival in the UE or by the establishment of GBR bearer with uplinkresource requirements. Preamble transmission may be triggered in thecase of UL data arrival, meaning that preamble transmission may betriggered by the BSR reception in the eNB and/or establishment of a nonGBR bearer with uplink data. Upon new UL data arrival, the UE may nottrigger an RA procedure on an SCell. The eNB may, selectively, triggerthe RA procedure based on the BSR reception due to UL data arrival inthe UE. eNB may consider many parameters in triggering an RA on anSCell. For example, parameters may include current eNB load, UE buffersize(s) in BSR report(s), UE category, UE capability, QoS requirements,GBR bearer requirements and/or the like. UE may determine that radioresources of the out-of-sync SCell may be required for uplink datatransmission.

In a second embodiment, in the sTAG sync process base station maytransmit a MAC timing advance command with a TAG index of theout-of-sync sTAG. The UE may use an stored value of N_TA for the out ofsync sTAG and apply the timing advance value in the MAC timing advancecommand to the stored N_TA of the sTAG. A UE may store or maintains N_TA(current timing advance value of an sTAG) upon expiry of associated timeAlignment Timer of the sTAG. The UE may apply the received timingadvance command MAC control element and starts associated time AlignmentTimer. This process may practically put the sTAG in an in-sync state.The base station may transmit one or more MAC timing advance commandsupon receiving uplink packets from the UE on the sTAG to align UE uplinktransmissions in the sTAG. It is up to eNB to select the first or secondembodiment for synchronizing the uplink of first SCell. For example, theeNB may operate in the second embodiment, if the SCell has not beenin-sync for a long time, or the sTAG has not been in-Sync since it hasbeen configured. In another example, the eNB may operate in the firstembodiment if the sTAG has recently entered an out-of-sync state. Inanother example, the eNB may operate in the second embodiment if theeNB-UE distance is relatively short, for example in the range of tens orhundreds of meters.

FIG. 10 is an example flow diagram illustrating base station signalingto schedule packets on a secondary cell as per an aspect of anembodiment of the present invention. According to some of the variousembodiments, a base station may be configured to communicate employing aplurality of cells with a wireless device. The plurality of cells may beassigned to a plurality of cell groups comprising: first cell group(s)and the second cell group.

The base station may receive a buffer status report on a first cell inactivated cell(s) in the plurality of cells from the wireless device at1000. The buffer status report may indicate an amount of data availablefor transmission in uplink buffer(s) of the wireless device. Each of theactivated cell(s) may be assigned by the base station to a cell group inat least one first cell group.

At 1002, the base station may transmit a control command fortransmission of a random access preamble on a second cell in theplurality of cells if the base station determines that radio resourcesof the second cell are required for transmission of a portion of thedata and that the second cell requires a first uplink timing that isdifferent from a second uplink timing of each of the at least one firstcell group. The buffer status report may be used, at least in part, tomake the determination. The control command may comprise: a mask index;and the random access preamble identifier.

The base station may receive the random access preamble on the secondcell at 1007. The second cell may be assigned to a second cell group.The transmission timing of the random access preamble may be determinedat least in part on a synchronization signal transmitted on an activatedcell of the second cell group. The second cell group may comprise asecond subset of the plurality of cells. The second subset may comprisean active secondary cell. Uplink transmissions in the secondary cellgroup may employ a second synchronization signal on the active secondarycell as a secondary timing reference. The activated cell of the secondcell group may be the second cell.

A random access response may be transmitted on a primary cell of aprimary cell group in the first cell group(s) at 1009. The random accessresponse may comprise a timing advance command for the second cellgroup. The primary cell group may comprise a first subset of the cells.The first subset may comprise the primary cell. Uplink transmissions bythe wireless device in the primary cell group may employ a firstsynchronization signal transmitted on the primary cell.

The base station may transmit control packet(s) at 1010 to providetransport format information and resource allocation information fortransmission of packets of the data to be transmitted on a first datachannel of the second cell.

According to some of the various embodiments, additional commands may betransmitted by the base station to the wireless device. For example, thebase station may send an activation command to activate the second cellin the wireless device. Another example includes transmitting controlmessage(s) to the wireless device. Some of the control message(s) may beconfigured to cause configuration of the second cell in the wirelessdevice. Other control message(s) may be configured to cause in thewireless device: configuration of the second cell in the plurality ofcells; and assignment of the second cell to the second cell group.Control message(s) may comprise radio resource control message(s).

According to some of the various embodiments, the base station may beconfigured to communicate employing a plurality of cells with a wirelessdevice. The base station may comprise: one or more communicationinterfaces; one or more processors; and memory storing instructions. Thememory storing instructions, when executed, may cause the base stationto perform a series of actions such as those described above.Additionally, the instructions may further cause the base station toreceive a second plurality of packets of the data on currently activatedand synchronized cells.

FIG. 11 is an example flow diagram illustrating base station signalingto schedule packets on a secondary cell as per an aspect of anembodiment of the present invention. According to some of the variousembodiments, a base station may be configured to communicate employing aplurality of cells with a wireless device. The plurality of cells may beassigned to a plurality of cell groups comprising: first cell group(s)and the second cell group.

According to some of the various embodiments, the base station maytransmit control message(s) on a first cell in activated cell(s) in theplurality of cells at 1100. The control message(s) may establish atleast one radio bearer, the at least one radio bearer may enable uplinkdata transmission with a guaranteed bit rate from the wireless device.Each of the activated cell(s) may be assigned by the base station to acell group in first cell group(s). The control message(s) may be furtherconfigured to modify a radio bearer. Additionally, according to some ofthe various embodiments, the base station may transmit controlmessage(s) to the wireless device to cause the configuration of theuplink random access resources.

At 1102, the base station may transmit a control command fortransmission of a random access preamble on a second cell in theplurality of cells if the base station determines that radio resourcesof the second cell are required for transmission of a portion of thedata and that the second cell requires a first uplink timing that isdifferent from a second uplink timing of each of the first cellgroup(s). The guaranteed bit rate may be used, at least in part, to makethe determination. The control command may comprise: a mask index; andthe random access preamble identifier. Control message may compriserandom access resource parameters. The random access resource parametersmay comprise an index, a frequency offset, sequence parameter(s), and/orthe like. The control command may comprise an index identifying thesecondary cell if the control command is not transmitted on a downlinkcarrier of the secondary cell.

The base station may receive the random access preamble on the secondcell at 1107. The second cell may be assigned to a second cell group.The transmission timing of the random access preamble may be determinedat least in part on a synchronization signal transmitted on an activatedcell of the second cell group. The second cell group may comprise asecond subset of the plurality of cells. The second subset may comprisean active secondary cell. Uplink transmissions in the secondary cellgroup may employ a second synchronization signal on the active secondarycell as a secondary timing reference. The activated cell of the secondcell group may be the second cell. The random access preamble may bereceived on uplink random access resources of the second cell.

A random access response may be transmitted by the base station at 1109.The random access response may comprise a timing advance command for thesecond cell group. The primary cell group may comprise a first subset ofthe cells. The first subset may comprise the primary cell. Uplinktransmissions by the wireless device in the primary cell group mayemploy a first synchronization signal transmitted on the primary cell.

The base station may transmit control packet(s) at 1110 to providetransport format information and resource allocation information fortransmission of packets of the uplink data to be transmitted on a firstdata channel of the second cell.

According to some of the various embodiments, additional commands may betransmitted by the base station to the wireless device. For example, thebase station may send timing advance command(s) to the wireless device.The timing advance command(s) may comprise: a time adjustment value; andan index identifying the second cell group. The timing advancecommand(s) causes substantial alignment of reception timing of uplinksignals in frames and subframes of the second cell group at the basestation.

Additional embodiments may comprise the base station receiving a bufferstatus report from the wireless device. The buffer status report mayindicate an amount of data available for transmission in uplinkbuffer(s) of the wireless device. The base station may transmit acontrol command for transmission of a random access preamble on a firstcell in the cells if the base station determines: that radio resourcesof the first cell are required for transmission of a portion of thedata; and that the first cell requires a different uplink timing fromall currently activated cells of the wireless device. The determinationmay be made, based at least in part, on the buffer status report. Thebase station may transmit control packet(s) to provide transport formatinformation and resource allocation information for transmission ofpackets of the data to be transmitted on a first data channel of thefirst cell.

Yet other embodiments may comprise the base station transmitting controlmessage(s) to the wireless device. The control message(s) may establishradio bearer(s). The radio bearer(s) may enable uplink data transmissionwith a guaranteed bit rate from the wireless device. The base stationmay transmit a control command for transmission of a random accesspreamble on a first cell in the cells if the base station determines:that radio resources of the second cell are required for transmission ofa portion of the uplink data; and that the first cell requires adifferent uplink timing from all currently activated cells of thewireless device. The determination may be made, based at least in part,on the guaranteed bit rate. The base station may transmit controlpacket(s) to provide transport format information and resourceallocation information for transmission of packets of the uplink data tobe transmitted on a first data channel of the first cell.

The mapping of a serving cell to a TAG may be configured by the servingeNB with RRC signaling. The mechanism for TAG configuration andreconfiguration may be based on RRC signalling. When needed, the mappingbetween an SCell and a TA group may be reconfigured with RRC signaling.In an example implementation, the mapping between an SCell and a TAG maynot be reconfigured with RRC while the SCell is configured. For exampleif there is a need to move an SCell from an sTAG to a pTAG, at least oneRRC message, for example, at least one RRC reconfiguration message, maybe send to the UE to reconfigure TAG configurations. The PCell may notchange its TA group and may always be a member of the pTAG.

According to some of the various aspects of embodiments, when an eNBperforms SCell addition configuration, the related TAG configuration maybe configured for the SCell. In an example embodiment, eNB may modifythe TAG configuration of an SCell by removing (releasing) the SCell andadding a new SCell (with the same physical cell ID and frequency) withan updated TAG ID. The new SCell with the updated TAG ID may beinitially inactive subsequent to joining the updated TAG ID. eNB mayactivate the updated new SCell and then start scheduling packets on theactivated SCell. In an example implementation, it may not be possible tochange the TAG associated with an SCell, but rather, the SCell may needto be removed and a new SCell may need to be added with another TAG.This may not require employing mobilityControlInfo in the RRCreconfiguration message.

An eNB may perform initial configuration based on initial configurationparameters received from a network node (for example a managementplatform), an initial eNB configuration, a UE location, a UE type, UECSI feedback, UE uplink transmissions (for example, data, SRS, and/orthe like), a combination of the above, and/or the like. For example,initial configuration may be based on UE channel state measurements. Forexample, depending on the signal strength received from a UE on variousSCells downlink carrier or by determination of UE being in a repeatercoverage area, or a combination of both, an eNB may determine theinitial configuration of sTAGs and membership of SCells to sTAGs.

In an example implementation, the TA value of a serving cell may change,for example due to UE's mobility from a macro-cell to a repeater or anRRH (remote radio head) coverage area. The signal delay for that SCellmay become different from the original value and different from otherserving cells in the same TAG. In this scenario, eNB may relocate thisTA-changed serving cell to another existing TAG. Or alternatively, theeNB may create a new TAG for the SCell based on the updated TA value.The TA value may be derived, for example, through eNB measurement(s) ofsignal reception timing, a RA mechanism, or other standard orproprietary processes. An eNB may realize that the TA value of a servingcell is no longer consistent with its current TAG. There may be manyother scenarios which require eNB to reconfigure TAGs. Duringreconfiguration, the eNB may need to move the reference SCell belongingto an sTAG to another TAG. In this scenario, the sTAG would require anew reference SCell. In an example embodiment, the UE may select anactive SCell in the sTAG as the reference timing SCell.

eNB may consider UE's capability in configuring multiple TAGs for a UE.UE may be configured with a configuration that is compatible with UEcapability. Multiple TAG capability may be an optional feature and perband combination Multiple TAG capability may be introduced. UE maytransmit its multiple TAG capability to eNB via an RRC message and eNBmay consider UE capability in configuring TAG configuration(s).

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g. to establish, modify and/or release RBs,to perform handover, to setup, modify, and/or release measurements, toadd, modify, and/or release SCells). As part of the procedure, NASdedicated information may be transferred from E-UTRAN to the UE. If thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList, the UE may perform an SCell release. If the receivedRRC Connection Reconfiguration message includes the sCellToAddModList,the UE may perform SCell additions or modification.

When a UE receives an sCellToAddModList in an RRC reconfigurationmessage, the UE may process the content of the message. The UE may, foran sCellIndex value included in the sCellToAddModList that is not partof the current UE configuration (SCell addition), add the SCellcorresponding to the cellIdentification in accordance with the receivedradioResourceConfigCommonSCell (SCell common configuration parameters)and radioResourceConfigDedicatedSCell (SCell dedicated configurationparameters). The UE may configure lower layers to consider the SCell tobe in a deactivated state. The UE may, for a sCellIndex value includedin the sCellToAddModList that is part of the current UE configuration(SCell modification), modify the SCell configuration in accordance withthe received radioResourceConfigDedicatedSCell.

According to some of the various aspects of embodiments, commonparameters may comprise downlink common parameters and uplink commonparameters. Examples of downlink common parameters include: downlinkbandwidth, antennaInfoCommon, mbsfn-SubframeConfigList, phich-Config,pdsch-ConfigCommon, and tdd-Config. Examples of uplink common parametersinclude: ul-CarrierFreq, ul-Bandwidth, p-Max,uplinkPowerControlCommonSCell, soundingRS-UL-ConfigCommon,ul-CyclicPrefixLength, prach-ConfigSCell (TDD), and pusch-ConfigCommon.Dedicated parameters may comprise downlink dedicated parameters anduplink dedicated parameters. Examples of downlink dedicated parametersinclude AntennaInfoDedicated, CrossCarrierSchedulingConfig,csi-RS-Config, pdsch-ConfigDedicated. Examples of uplink dedicatedparameters include antennaInfoUL, pusch-ConfigDedicatedSCell,uplinkPowerControlDedicatedSCell, cqi-ReportConfigSCell,soundingRS-UL-ConfigDedicated, soundingRS-UL-ConfigDedicated,soundingRS-UL-ConfigDedicatedAperiodic, and pathlossReferenceLinking.The names of these variables and example definition(s) and format forthese variables may be found in releases of LTE RRC standarddocumentation.

In an example embodiment, SCell TAG configuration(s) (e.g. TAG IDassignment) may be included in sCellToAddModList or one of the IEs insCellToAddModList. A TAG ID may be included in the TAG configuration ofa cell. The TA group may be configured when an SCell is added. Thus theconfiguration of a TA group may be seen as part of the SCelladdition/modification. A dedicated parameter in SCell dedicatedparameters may include the TAG ID of the SCell if the SCell belongs toan sTAG. If a dedicated TAG id parameter is not included in dedicatedradio resource configuration of an SCell, it may be assumed that theSCell is assigned to the pTAG. This may be an implicit assignment of theSCell to pTAG. According to some of the various aspects of embodiments,some of the TAG configuration parameters may be included in commonconfiguration parameters and some other TAG configuration parameters maybe included in dedicated configuration parameters. SCellToAddModListtransmitted to a UE may comprise one or more of: an sCell Index, aphysical Cell Id, a downlink Carrier Frequency, aradioResourceConfigCommonSCell, and a radioResourceConfigDedicatedSCell.radioResourceConfigDedicatedSCell IE in sCellToAddModList transmitted toa UE (in RRC message(s)) may comprise the TAG ID that the SCell belongsto. A TA group configuration may be UE-specific (a dedicatedconfiguration parameter). The identity or index of a TA group which anSCell belongs to, a TA group identity (TAG ID), may be assigned to aSCell employing an dedicated parameter inradioResourceConfigDedicatedSCell. When an SCell is released, the TAGassignment of the SCell may also be released. eNB may not be needed toinclude TAG ID in sCellToReleaseList. Each Cell may be assigned a TAG ID(implicitly or explicitly). If an SCell is not assigned a TAG ID, theSCell may be considered belonging to the pTAG by default. Implicitassignment of SCells to pTAG may reduce the signaling overhead. It isexpected that in many operating scenarios, sTAGs are not configured, andtherefore transmission of pTAG index for the configured SCells isavoided. This may increase spectral efficiency and would reducesignaling overhead.

A TAG ID may be UE specific, and each UE may have its own TAGconfiguration. For example, a given SCell may be a part of the pTAG inone UE and a part of an sTAG in another UE. In this embodiment, theSCell configuration may include TAG Index. Assignment of an SCell to ansTAG may be UE specific, and may be different for different UEsconnected to the same eNB. For example, a UE in the coverage of arepeater connected to the eNB may have a different sTAG configurationthan a UE which is directly connected to the same eNB.

According to some of the various aspects of embodiments,MAC-Config-Dedicated parameter in an RRC connection reconfigurationmessage may include a dedicated TAT parameter for each of the timealignment groups configured in the UE. In this example embodiment, a TATmay be included in MAC Dedicated parameters. If TAT for an sTAG isreceived in MAC-Dedicated parameters, the UE may consider the dedicatedparameter. For an SCell in an sTAG, the UE may not consider timealignment timer in the SIB parameter received from an eNB, instead theUE may consider the time alignment configuration parameter in theMAC-Dedicated parameters. Different UEs may be required to be configuredwith different TAT values in an optimized network operation. UE TATvalue may be optimized depending on eNB-UE distance, UE speed, UEcategory, and/or the like. Therefore, it is not recommended to use acommon variable for time alignment timer of secondary cell groups.

The TA maintenance for PCell may follow Rel-10 principles. If an SCellapplying the TA of PCell is added, the Rel-10 procedures may be reused.In one example embodiment, there is no need to explicitly assign a TAGID for cells in the pTAG. SCells configured with the pTAG may be groupedimplicitly and a TAG ID for pTAG may not be needed or a TAG ID may beassigned implicitly by default (for example, TAGID: 0). TAG identity maybe regarded as zero if the TAG identity field is absent in SCelldedicated parameters upon SCell addition. If an SCell is not configuredwith a TAG ID, it may apply that the SCell belongs to the pTAG.

According to some of the various aspects of embodiments, sTAGconfigurations may be released upon re-establishment or handover. TAGrelated configuration may include TAG ID, TAG-specific TAT, and/or theserving cells associated with it. In an example embodiment MAC dedicatedparameters IE may include a TAG configuration information elementcomprising a sequence of one or more TAG ID and TAT for configured TAGs.In an example embodiment the TAG configuration information element mayalso comprise the list of SCells belonging to the TAG. The associationbetween SCells with TAG IDs may be included in SCell configuration IEparameters, or may be included in TAG configuration information element.

The parameters related to SCell random access channel may be common toall UEs. For example PRACH configuration (RACH resources, configurationparameters, RAR window) for the SCell may be common to all UEs. RACHresource parameters may include prach-configuration index, and/orprach-frequency offset. SCell RACH common configuration parameters mayalso include power: power ramping parameter(s) for preambletransmission; and max number of preamble transmission parameter. It ismore efficient to use common parameters for RACH configuration, sincedifferent UEs will share the same random access channel. Using dedicatedparameters for SCell RACH configuration is not preferred since it willincrease the size of the radio resources required for random accessprocess, and may reduce spectral efficiency.

In an example implementation, TAT of an sTAG may not be running when thelast SCell of the group is removed from the TA group. The eNB may removesTAG when removing the last SCell from the sTAG. When sTAG is removedthe TAT for sTAG may be stopped and the NTA value may be discarded.According to some of the various aspects of embodiments, sTAG TATconfiguration may be released when no SCell is configured in the sTAG.When sTAG is released, then TAT is also released/de-configured (e.g.this may be achieved by de-configuring the timer). Upon sTAG depletion,the TAT may be de-configured by the eNB, which may implicitly stop theTAT of this group at the same time. If an sTAG is empty, the same RRCmessage may remove the sTAG and TAT and a removed sTAG may bereleased/de-configured. In another example embodiment, TAT may bestopped but a TAT entity may be maintained.

eNB may transmit at least one RRC message to configure PCell, SCell(s)and RACH, and TAG configuration parameters. MAC-MainConfig may include atimeAlignmentTimerDedicated IE to indicate time alignment timer valuefor the pTAG. MAC-MainConfig may further include an IE including asequence of at least one (sTAG ID, and TAT value) to configure timealignment timer values for sTAGs. In an example, a first RRC message mayconfigure TAT value for pTAG, a second RRC message may configure TATvalue for sTAG1, and a third RRC message may configure TAT value forsTAG2. There is no need to include all the TAT configurations in asingle RRC message. The IE including a sequence of at least one (sTAGID, and TAT) value may also be used to update the TAT value of anexisting sTAG to an updated TAT value. The at least one RRC message mayalso include sCellToAddModList including at least one SCellconfiguration parameters. The radioResourceConfigDedicatedSCell(dedicated radio configuration IEs) in sCellToAddModList may include anSCell MAC configuration comprising TAG ID for the corresponding SCelladded or modified. The radioResourceConfigDedicatedSCell may alsoinclude pathloss reference configuration for an SCell. If TAG ID is notincluded in SCell configuration, the SCell is assigned to the pTAG. Inother word, a TAG ID may not be included inradioResourceConfigDedicatedSCell for SCells assigned to pTAG. TheradioResourceConfigCommonSCell (common radio configuration IEs) insCellToAddModList may include RACH resource configuration parameters,preamble transmission power control parameters, and other preambletransmission parameter(s). At the least one RRC message configuresPCell, SCell, RACH resources, and/or SRS transmissions and may assigneach SCell to an sTAG (implicitly or explicitly). PCell is alwaysassigned to the pTAG.

The pathloss reference IE (pathlossReferenceLinking) inradioResourceConfigDedicatedSCell may indicate whether the UE shallapply as pathloss reference either: the downlink of the PCell, or of theSIB2 downlink of the SCell that corresponds with the configured uplink.For SCells part of a secondary TAG eNB may only configure the pathlossreference to SIB2 downlink of the SCell that corresponds with theconfigured uplink. If a serving cell belongs to a TAG containing theprimary cell then, for the uplink of the primary cell, the primary cellis used as the reference serving cell for determining reference SignalPower. For the uplink of the secondary cell, the serving cell configuredby the RRC parameter pathloss Reference Linking IE is used as thereference serving cell for determining reference signal power. If aserving cell belongs to an sTAG then the serving cell is used as thereference serving cell for determining reference signal power.

According to some of the various aspects of embodiments, a base stationmay transmit at least one control message to a wireless device in aplurality of wireless devices. The at least one control message may beconfigured to cause, in the wireless device, configuration of at least:

a) a plurality of cells. Each cell may comprise a downlink carrier andzero or one uplink carrier. The configuration may assign a cell groupindex to a cell in the plurality of cells. The cell group index mayidentify one of a plurality of cell groups. A cell group in theplurality of cell groups may comprise a subset of the plurality ofcells. The subset may comprise a reference cell with a referencedownlink carrier and a reference uplink carrier. Uplink transmissions bythe wireless device in the cell group may employ a synchronizationsignal transmitted on the reference downlink carrier as timingreference.

b) a plurality of MAC dedicated parameters comprising a sequence of atleast one element. An element in the sequence may comprises a timealignment timer value and a secondary time alignment group index. pTAGtime alignment timer value may be included as a dedicated IE in MAC mainconfiguration parameter (a dedicated IE). Each time alignment timervalue being selected, by the base station, from a finite set ofpredetermined values. The time alignment timer value in the sequence maybe associated with a cell group index that is specified in the sameelement. In an example embodiment, the element may also comprise thelist of cell indexes associated with the time alignment group index.

c) a time alignment timer for each cell group in the plurality of cellgroups.

The base station may transmit a plurality of timing advance commands.Each timing advance command may comprise: a time adjustment value, and acell group index. A time alignment timer may start or may restart whenthe wireless device receives a timing advance command to adjust uplinktransmission timing on a cell group identified by the cell group index.The cell group may be considered out-of-sync, by the wireless device,when the associated time alignment timer expires or is not running. Thecell group may be considered in-sync when the associated time alignmenttimer is running.

The timing advance command may causes substantial alignment of receptiontiming of uplink signals in frames and subframes of all activated uplinkcarriers in the cell group at the base station. The time alignment timervalue may be configured as one of a finite set of predetermined values.For example, the finite set of predetermined values may be eight. Eachtime alignment timer value may be encoded employing three bits. TAG TATmay be a dedicated time alignment timer value and is transmitted by thebase station to the wireless device. TAG TAT may be configured to causeconfiguration of time alignment timer value for each time alignmentgroup. The IE TAG TAT may be used to control how long the UE isconsidered uplink time aligned. It corresponds to the timer for timealignment for each cell group. Its value may be in number of sub-frames.For example, value sf500 corresponds to 500 sub-frames, sf750corresponds to 750 sub-frames and so on. An uplink time alignment iscommon for all serving cells belonging to the same cell group. In anexample embodiment, the IE TAG TAT may be defined as: TAGTAT::=SEQUENCE{TAG ID, ENUMERATED {sf500, sf750, sf1280, sf1920, sf2560,sf5120, sf10240, infinity}. Time alignment timer for pTAG may beindicated in a separate IE and may not be included in the sequence.

In an example, TimeAlignmentTimerDedicated IE may be sf500, and then TAGTAT may be {1, sf500; 2, sf2560; 3, sf500}. In the example, timealignment timer for the pTAG is configured separately and is notincluded in the sequence. In the examples, TAG0 (pTAG) time alignmenttimer value is 500 subframes (500 m-sec), TAG1 (sTAG) time alignmenttimer value is 500 subframes, TAG2 time alignment timer value is 2560subframes, and TAGS time alignment timer value is 500 subframes. This isfor example purposes only. In this example a TAG may take one of 8predefined values. In a different embodiment, the enumerated valuescould take other values. The size of the sequence is 3 in the firstexample and 4 in the second example. In another example embodiment, thesize could be 2, 3, equal to the size of configured TAGs in the wirelessdevice, and/or the like.

FIG. 12 is an example flow diagram illustrating signaling mechanism toconfigure a plurality cells and a plurality of cell groups as per anaspect of an embodiment of the present invention. According to some ofthe various embodiments, a base station may be configured to communicatewith wireless device(s) employing a plurality of cells. The wirelessdevice(s) may be compatible with LTE release 11 or above and support theconfiguration of multiple cell groups.

The base station may transmit control message(s) to the wireless deviceat 1200. The control message may be configured to cause in the wirelessdevice configuration of secondary cell(s) in the plurality of cells. Thecontrol message may comprise common parameters for a secondary cell inthe secondary cell(s). The common parameters may have the same value formultiple wireless devices. The control message may comprise randomaccess resource and power control parameter(s). The random accessresource parameters may identify random access resources. The controlmessage may also comprise dedicated parameter(s). The dedicatedparameter(s) may be specific to wireless device(s). The dedicatedparameter(s) may comprise a cell group index for the secondary cell, anda time alignment timer parameter for each cell group in the plurality ofcell groups. The control message(s) may comprise a time alignment timervalue for a time alignment timer of the secondary cell group.

The cell group index may identify one of the cell groups. The cellgroups may comprise a primary cell group and a secondary cell group. Thecell groups may comprise: a primary cell group comprising a first subsetof said plurality of cells; and the secondary cell group. The firstsubset may comprise the primary cell. The secondary cell group maycomprise a second subset of the secondary cell(s) comprising thesecondary cell.

According to some of the various embodiments, control message(s) may beconfigured to further cause configuration of a time alignment timer foreach of the cell group(s) in the wireless device. The time alignmenttimer may start or restart in response to the wireless device receivinga timing advance command to adjust uplink transmission timing of acommanded cell group in the plurality of cell groups.

The wireless device may be assigned media access control dedicatedparameter(s) by the configuration. The plurality of media access controldedicated parameters may comprise time alignment timer value(s). Each ofthe time alignment timer value(s) may be associated with a unique cellgroup in the wireless device.

According to some of the various embodiments, the base station maytransmit a control command to the wireless device at 1202. The controlcommand may be configured to cause transmission of a random accesspreamble on the random access resources of the secondary cell in thesecondary cell group. The transmission power of the random accesspreamble may be calculated employing the power control parameter(s). Thecontrol command may further comprise an index identifying the secondarycell if the control command is transmitted on a cell different from thesecondary cell.

According to some of the various embodiments, the base station maytransmit a random access response on a primary cell in the primary cellgroup at 1204. The random access response may comprise a timing advancecommand for the secondary cell group comprising the secondary cell.

According to some of the various embodiments, the base station mayreceive the random access preamble on the random access resources.Transmission timing of the random access preamble may be determined, atleast in part, employing a second synchronization signal transmitted onone of the activated cell(s) in the secondary cell group.

According to some of the various embodiments, base station may transmittiming advance command(s) to the wireless device. The timing advancecommand(s) may comprise: a time adjustment value; and an indexidentifying the secondary cell group. Uplink signals transmitted by thewireless device in the secondary cell group may employ the secondsynchronization signal as a timing reference. Additionally, timingadvance command(s) may be configured to cause substantial alignment ofreception timing of the uplink signals in frames and subframes of thesecondary cell group at the base station. The uplink signals may betransmitted by the wireless device in the primary cell group employ afirst synchronization signal transmitted on the primary cell as a firsttiming reference; and the secondary cell group employ a secondsynchronization signal transmitted on one of the activated cell(s) inthe secondary cell group as a second timing reference. The secondarycell may be the timing reference for uplink transmissions in thesecondary cell group by said wireless device if the size of the secondsubset is one.

According to some of the various embodiments, a first signaling bearermay be established between the base station and the wireless deviceprior to transmitting the control message(s). The establishing maycomprising the base station transmitting a control message to thewireless device on the primary cell. Additionally, prior to transmittingthe control message(s), the base station may receive radio capabilityparameters from the wireless device on the first signaling bearer on theprimary cell. The radio capability parameters may indicate that thewireless device supports configuration of the cell groups.

According to some of the various embodiments, a base station may beconfigured to communicate employing a plurality of cells. The basestation may comprise communication interface(s), processor(s) andmemory. The memory may store instructions. The processors may beconfigured to execute the stored instructions to perform variousprocesses as described herein.

FIG. 13 is an example flow diagram illustrating a signaling mechanism toconfigure a plurality cells and a plurality of cell groups as per anaspect of an embodiment of the present invention.

A control message from a base station may be received by a wirelessdevice at 1300. The base station may be configured to communicateemploying a plurality of cells. The control message(s) may cause in thewireless device, configuration of secondary cell(s) in the plurality ofcells. The control message may comprise common parameters for asecondary cell in the secondary cell(s). The common parameters may havethe same value for multiple wireless devices. The control message maycomprise random access resource and power control parameter(s). Therandom access resource parameters may identify random access resources.The control message may also comprise dedicated parameter(s). Thededicated parameter(s) may be specific to wireless device(s). Thededicated parameter(s) may comprise a cell group index for the secondarycell, and a time alignment timer parameter for each cell group in theplurality of cell groups. The resource parameters may identify randomaccess resources. The secondary cell may be in a secondary cell group.

The control message(s) may be configured to further cause in thewireless device, configuration of a time alignment timer for each of thecell groups. The time alignment timer may start or restart in responseto the wireless device receiving a timing advance command to adjustuplink transmission timing of a commanded cell group in the plurality ofcell groups. Control message(s) may comprise a media access controldedicated information element. The media access control dedicatedinformation element may comprise a sequence of first informationelement(s). Each of the first information element(s) may comprise: afirst cell group index of a first secondary cell group and a first timealignment timer for the first secondary cell group. Control message(s)may set up or modify radio bearer(s).

According to some of the various embodiments, the wireless device mayreceive a control command at 1302. The control command may be configuredto cause transmission of a random access preamble on the random accessresources of the secondary cell. The transmission power of the randomaccess preamble may be calculated employing the power controlparameter(s). The power control parameter(s) may comprise: a powerramping step; and an initial preamble received target power.

According to some of the various embodiments, the wireless device mayreceive a random access response at 1304. The random access response maycomprise a timing advance command for a secondary cell group comprisingthe second cell.

FIG. 12 is an example flow diagram illustrating signaling mechanism toconfigure a plurality cells and a plurality of cell groups as per anaspect of an embodiment of the present invention. According to some ofthe various embodiments a base station may be configured to communicateto wireless devices employing a plurality of cells. The wirelessdevice(s) may be compatible with LTE release 11 or above and support theconfiguration of multiple cell groups.

According to some of the various embodiments, the base station maytransmit control message(s) to a wireless device in a plurality ofwireless devices at 1200. The control message may be configured to causethe configuration of at least one secondary cell(s) in the plurality ofcells in the wireless device. The control message may be configured tocause in the wireless device the assignment of each of the secondarycell(s) to a cell group in a plurality of cell groups. The cell group(s)may comprise a primary cell group and secondary cell group(s). Theprimary cell group may comprise a first subset of the plurality ofcells. The first subset may comprise a primary cell. Uplinktransmissions by the wireless device in the primary cell group mayemploy a first synchronization signal transmitted on the primary cell.The first secondary cell group in the secondary cell group(s) maycomprise a second subset of the secondary cell(s). The second subset maycomprise a reference secondary cell. Uplink transmissions in thesecondary cell group may employ a second synchronization signal on thereference secondary cell as a secondary timing reference. The referencesecondary cell may be an activated cell in the secondary cell group.

The control message(s) may comprise dedicated parameter(s) specific tothe wireless device. For each of the secondary cell(s), if the dedicatedparameter(s) comprise a cell group index for the secondary cell, thesecondary cell may be assigned to one of the secondary cell group(s)identified by the cell group index. Otherwise (if the dedicatedparameters do not comprise a cell group index for the secondary cell),the secondary cell may be assigned to the primary cell group. Theprimary cell group may be identified by a group index equal to zero.

Control message(s) may comprise at least one cell-add-modify informationelement. Each of the cell-add-modify information element(s) maycomprises a first plurality of dedicated parameters in the dedicatedparameter(s). The first plurality of dedicated parameters may comprise afirst cell index for a first secondary cell in the secondary cell(s).The dedicated parameter(s) may further comprise a time alignment timerparameter for each cell group in the plurality of cell groups.

Control message(s) may be configured to further cause in the wirelessdevice configuration of a time alignment timer for each of the pluralityof cell groups. The time alignment timer may start or restart inresponse to the wireless device receiving a timing advance command toadjust uplink transmission timing of a commanded cell group in theplurality of cell groups. The base station may transmit at least onetiming advance command to the wireless device. The timing advancecommand may comprise: a time adjustment value; and an index identifyingthe secondary cell group. The timing advance command(s) may beconfigured to cause substantial alignment of reception timing of theuplink signals in frames and subframes of the secondary cell group atthe base station.

The control message(s) may comprise a media access control dedicatedinformation element. The media access control dedicated informationelement may comprise a sequence of first information element(s). Each ofthe first information element(s) may comprise: a first cell group indexof a first secondary cell group; and a first time alignment timer forthe first secondary cell group. Media access control dedicatedinformation element may further comprise a deactivation timer for thesecondary cell(s).

According to some of the various embodiments, the base station maytransmit a control command configured to cause transmission of a randomaccess preamble on random access resources of a secondary cell in thesecondary cell group at 1202. The base station may receive the randomaccess preamble on the random access resources. Transmission timing ofthe random access preamble may be determined, at least in part,employing the second synchronization signal.

According to some of the various embodiments, the base station maytransmit a random access response at 1204. The random access responsemay comprise a timing advance command for the secondary cell group.

According to some of the various embodiments, the base station maytransmit other commands. For example, the base station may transmit atiming advance command to the wireless device. The timing advancecommand may be configured to cause substantial alignment of receptiontiming of uplink signals in frames and subframes of a cell group at thebase station. The timing advance command may comprise an indexidentifying the cell group.

According to some of the various embodiments, the base station maycomprise communication interface(s), processor(s), and memory. Thememory may store instructions. The processor(s) may execute theinstructions to cause actions described herein.

FIG. 13 is an example flow diagram illustrating a signaling mechanism toconfigure a plurality cells and a plurality of cell groups as per anaspect of an embodiment of the present invention.

A control message from a base station may be received by a wirelessdevice at 1300. The base station may be configured to communicate withthe wireless device employing a plurality of cells. The controlmessage(s) may cause in the wireless device, configuration of secondarycell(s) in the plurality of cells. The control message(s) may cause inthe wireless device, assignment of each of the secondary cell(s) to acell group in a plurality of cell groups. The plurality of cell groupsmay comprise a primary cell group and secondary cell group(s). Theprimary cell group may comprise a first subset of the plurality ofcells. The first subset may comprise a primary cell. The first secondarycell group in the secondary cell group(s) may comprise a second subsetof the secondary cell(s).

The control message may comprise dedicated parameter(s). The dedicatedparameter(s) may be specific to wireless device(s) in a plurality ofwireless devices. If the dedicated parameter(s) may comprise a cellgroup index for the secondary cell, the secondary cell may be assignedto one of the secondary cell group(s) identified by the cell groupindex. Otherwise, the secondary cell may be assigned to the primary cellgroup. The secondary cell may be in a secondary cell group. Thededicated parameter(s) may comprise a first dedicated parameterapplicable to all activated secondary cells in secondary cell(s). Thededicated parameter(s) may comprise a second dedicated parameter beingsecondary cell specific and being applicable to only one secondary cellin the secondary cell(s).

The control message(s) may be configured to further cause in thewireless device, configuration of a time alignment timer for each of thecell groups. The time alignment timer may start or restart in responseto the wireless device receiving a timing advance command to adjustuplink transmission timing of a commanded cell group in the plurality ofcell groups.

According to some of the various embodiments, the wireless device mayreceive a control command at 1302. The control command may be configuredto cause transmission of a random access preamble on the random accessresources of the secondary cell in the secondary cell group.

According to some of the various embodiments, the wireless device mayreceive a random access response at 1304. The random access response maycomprise a timing advance command for a secondary cell group.

According to some of the various embodiments, the wireless device mayreceive a timing advance command from the base station. The timingadvance command may be configured to cause substantial alignment ofreception timing of uplink signals in frames and subframes of a cellgroup at the base station. The timing advance command may comprising anindex identifying the cell group.

FIG. 14 is an example flow diagram illustrating a signaling mechanism toconfigure a pathloss reference for secondary cells in a plurality ofcell groups as per an aspect of an embodiment of the present invention.According to some of the various embodiments a base station may beconfigured to communicate to wireless devices employing a plurality ofcells. The wireless device(s) may be compatible with LTE release 11 orabove and support the configuration of multiple cell groups.

According to some of the various embodiments, the base station maytransmit control message(s) to a wireless device at 1400. The controlmessage may be configured to cause in said wireless device configurationof secondary cell(s) in said plurality of cells. The control message maybe configured to assign each of the secondary cell(s) to a cell group ina plurality of cell groups. The plurality of cell groups may comprise: aprimary cell group and a secondary cell group. The primary cell groupmay comprise a first subset of the plurality of cells. The first subsetmay comprise a primary cell. Uplink transmissions by the wireless devicein the primary cell group may employ a first synchronization signaltransmitted on the primary cell. The secondary cell group may comprise asecond subset of the secondary cell(s). The second subset may comprise areference secondary cell. Uplink transmissions in the secondary cellgroup may employ a second synchronization signal on the referencesecondary cell as a secondary timing reference.

According to some of the various embodiments, the control message maycomprise a plurality of dedicated parameters for a secondary cell in thesecondary cell(s). The plurality of dedicated parameters may be specificto the wireless device. The plurality of dedicated parameters maycomprise a pathloss reference for the secondary cell. The pathlossreference may be a configurable parameter if the secondary cell is inthe primary cell group. The configurable parameter may be configurableto a downlink of the secondary cell or a downlink of the primary cell.The pathloss reference may only be configurable as a downlink of thesecondary cell if the secondary cell is in the secondary cell group.

According to some of the various embodiments, the plurality of dedicatedparameters may include: a cell group index for the secondary cell; and atime alignment timer parameter for each cell group in the plurality ofcell groups. The cell group index may identify one of a plurality ofcell groups. The plurality of cell groups may comprise a primary cellgroup and a secondary cell group.

According to some of the various embodiments, the control message(s) maybe configured to cause in the wireless device configuration of a timealignment timer for each of the plurality of cell groups. The timealignment timer may start or restart in response to the wireless devicereceiving a timing advance command to adjust uplink transmission timingof a commanded cell group in the plurality of cell groups.

According to some of the various embodiments, the control message(s) maycomprise a media access control dedicated information element. The mediaaccess control dedicated information element may comprise a sequence offirst information element(s). Each of the first information element(s)may comprise: a first cell group index of a first secondary cell group;and a first time alignment timer for the first secondary cell group.

According to some of the various embodiments, the control message(s) maycomprise a pathloss reference for a secondary cell in the secondarycell(s). The pathloss reference may be a configurable parameter if thesecondary cell is in the primary cell group. The configurable parametermay be configurable to one of the following: a downlink of the secondarycell; and a downlink of the primary cell. The pathloss reference may beonly configurable as a downlink of the secondary cell if the secondarycell is in the secondary cell group.

According to some of the various embodiments, the base station mayreceive uplink signals in the secondary cell from the wireless device at1402. Transmission power of the uplink signals may be determined, atleast in part, employing a received power of the pathloss referenceassigned to the secondary cell. According to some of the variousembodiments, the transmission power of the uplink signals may bedetermined, at least in part, employing measurements of the receivedpower of the pathloss reference assigned to the secondary cell.According to some of the various embodiments, the transmission power ofthe uplink signals may be determined, at least in part, furtheremploying at least one power control parameter in the controlmessage(s). According to some of the various embodiments, thetransmission power of the uplink signals may be determined, at least inpart, further employing power control commands transmitted by the basestation.

According to some of the various embodiments, the base station maytransmit a control command configured to cause transmission of a randomaccess preamble on random access resources of the secondary cell in thesecondary cell group. The transmission power of the random accesspreamble may be calculated employing the received power of the pathlossreference assigned to the secondary cell.

According to some of the various embodiments, the base station maytransmit a control packet(s) for providing transport format information,resource allocation information, and power control commands fortransmission of a plurality of packets to be transmitted on a first datachannel of the secondary cell. Transmission power of the plurality ofpackets may be calculated employing, at least in part: the receivedpower of the pathloss reference assigned to the secondary cell; and thepower control commands.

According to some of the various embodiments, several actions may betaken by the base station prior to transmitting the control message(s).A first signaling bearer may be established between the base station andthe wireless device. The establishing may comprise the base stationtransmitting a control message to the wireless device on the primarycell. The base station may receive a plurality of radio capabilityparameters from the wireless device on the first signaling bearer on theprimary cell. The plurality of radio capability parameters may indicatethat the wireless device supports configuration of the plurality of cellgroups.

According to some of the various embodiments, the base station maycomprise communication interface(s), processor(s), and memory. Thememory may store instructions. The processor(s) may execute theinstructions to cause the base station to take actions described herein.

FIG. 15 is an example flow diagram illustrating a signaling mechanism toconfigure pathloss reference for secondary cells in a plurality of cellgroups as per an aspect of an embodiment of the present invention.According to some of the various embodiments, the wireless device maycomprise communication interface(s), processor(s), and memory. Thememory may store instructions. The processor(s) may execute theinstructions to cause the wireless device to take actions describedherein.

According to some of the various embodiments, the wireless device mayreceive control message(s) from a base station at 1500. The base stationconfigured to communicate with the wireless device employing a pluralityof cells. The control message(s) may cause in the wireless device theconfiguration of at least one secondary cell in the plurality of cells.The control message(s) may cause in the wireless device, the assignmentof each of the secondary cell(s) to a cell group in a plurality of cellgroups. The plurality of cell groups may comprise a primary cell groupand a secondary cell group. The primary cell group may comprise a firstsubset of the plurality of cells. The first subset may comprise aprimary cell. The secondary cell group may comprise a second subset ofthe secondary cell(s).

According to some of the various embodiments, the control message(s) maycomprise a pathloss reference for a secondary cell in the secondarycell(s). The pathloss reference may be a configurable parameter if thesecondary cell is in the primary cell group. The configurable parametermay be configurable to one of the following: a downlink of the secondarycell; and a downlink of the primary cell. The configurable parameter maybe only configurable as a downlink of the secondary cell if thesecondary cell is in the secondary cell group.

According to some of the various embodiments, the control message(s) maycomprises cell-add-modify information element(s). Each of thecell-add-modify information element(s) may comprise a first plurality ofdedicated parameters in the plurality of dedicated parameters. The firstplurality of dedicated parameters may comprise a first cell index for afirst secondary cell in the secondary cell(s) if the first secondarycell is assigned to a secondary cell group.

According to some of the various embodiments, uplink signals may betransmitted in the secondary cell to the base station at 1502.Transmission power of the uplink signals may be determined, at least inpart, employing a received power of the pathloss reference assigned tothe secondary cell.

According to some of the various embodiments, the wireless device mayreceive at timing advance command(s) from the base station. The timingadvance command(s) may comprise: a time adjustment value; and an indexidentifying the secondary cell group. The timing advance command(s) maybe configured to cause substantial alignment of reception timing ofuplink signals in frames and subframes of the secondary cell group atthe base station.

According to some of the various embodiments, the wireless device may beassigned a plurality of media access control dedicated parameters by theconfiguration. The plurality of media access control dedicatedparameters may comprise a plurality of time alignment timer values. Eachtime alignment timer value may be associated with a unique cell grouptime alignment timer in the wireless device.

According to some of the various embodiments, the wireless device mayreceive from the base station control packet(s) for providing transportformat information, resource allocation information, and power controlcommands for transmission of a plurality of packets to be transmitted ona first data channel of the secondary cell. Transmission power of theplurality of packets may be calculated employing, at least in part: thereceived power of the pathloss reference assigned to the secondary cell;and the power control commands.

FIG. 9 is an example physical random access channel (PRACH)configuration in a primary TAG (pTAG) and a secondary TAG (sTAG) as peran aspect of an embodiment of the present invention. As shown in theexample, PRACH resources are configured for the PCell in pTAG and SCell2and SCell3 in sTAG. SCell1 and SCell4 are not configured with PRACHresources. This is an example and other configurations are alsopossible. In an example embodiment, no SCell in pTAG is configured withPRACH resources. In another example embodiment, PRACH resources for anSCell in pTAG may be configured, but eNB is not configured to trigger apreamble transmission on PRACH resources of an SCell in pTAG. Basically,PRACH resources in SCells in pTAG cannot be used for preambletransmissions by a UE.

For pTAG, there may not be a need to have more than one PRACH resourcefor a UE configured with multiple serving cells in pTAG because thePCell is always activated as long as the UE is in connected mode. Theremay not be a need to use RACH on the SCells in the TA group comprisingthe PCell. The TA maintenance of the TA group containing the PCell isbased, at least in part, on preamble transmitted on PCell PRACHresource. Even if PRACH resources on an SCell assigned to pTAG isconfigured in a UE, the eNB is configured not to transmit PDCCH orderfor transmission of preambles on an SCell assigned to pTAG. Therefore, aUE may not use PRACH of an SCell of the pTAG for preamble transmissionin the uplink.

In an sTAG, PRACH may be configured for more than one SCell. This mayintroduce flexibility for the network to balance the load on PRACHbetween cells. sTAG may have multiple SCells with PRACH because an SCellmay be deactivated. A UE may change the timing reference for example,when the timing reference SCell is deactivated or moved to another sTAG.In an example embodiment, for a UE, the timing reference may be theSCell sending the PRACH preamble and the initial timing acquisition maybe made by the PRACH transmission. If needed, RACH may be configured formultiple SCells in the sTAG and the RACH procedure for the sTAG may becarried out on any of those SCell within the sTAG. Configuring PRACH inmore than one SCell in an sTAG may provide flexibility for random accessprocess and preamble transmission. An eNB may transmit PDCCH order forpreamble transmission on any of the activated SCells in an sTAG withconfigured PRACH resources.

For an SCell TA group, RACH may be performed on an SCell in the SCell TAgroup based on the PDCCH order. For the network initiated RACH, thechoice of SCell to perform RACH may be left to eNB implementation basedon, for example, the radio quality of SCells, network load, and/or thelike. For example, when a UE moves in or out of the coverage area of arepeater or RRH (remote radio head) its sTAG and/or pTAG configurationmay change (for example, reference timing SCell may change). eNB maydetect this event by monitoring uplink transmissions, eNB measurements,or UE feedback. There may be no need to fix a specific SCell in an SCellgroup for RACH. It may be left to the eNB to decide which SCell to pickfor RACH. eNB may select the SCell for RACH. SCells in pTAG may notinclude PRACH resource and/or their PRACH resources may not becommunicated to the UE, but one or more SCells in sTAG may have PRACHresource. Configuration of pCell is UE specific. An SCell for a givenUE1 may be a PCell for another UE2. A UE may not receive PRACHconfiguration for an SCell in a pTAG (or the UE may ignore PRACHconfiguration for an SCell in pTAG if the UE receives pTAG SCell PRACHconfiguration). A UE may not be configured to transmit random accesspreamble on an SCell in a pTAG. In an example implementation, an SCellfor UE1, which may be a PCell for UE2, may have PRACH resources, but itsPRACH resources may not be communicated to UE1 or when it iscommunicated, UE1 may not use it for preamble transmission. In anexample embodiment, an eNB may configure PRACH resources on an SCell ofa pTAG, but the UE may not use those PRACH resources for preambletransmission.

If the multiple SCells in the same TA group are configured with the RACHparameters, the preamble usage efficiency may increase. eNB may selectthe SCell where the UE is asked to perform the RA procedure and thenallocate the dedicated preamble of the selected SCell to the UE. An eNBmay configure RACH parameters to more than one SCell in an sTAG. SCellRACH is triggered by the eNB and the SCell RACH may be contention-free.In such a configuration, eNB may select SCell and PRACH resource andpreamble ID for a UE. Then UE starts the PRACH process by sending thepreamble on the PRACH resource of the SCell selected by eNB. In pTAGoperation, UEs may use the same uplink carrier PRACH resource in PCelland use the same PCell timing reference. In sTAG operation, a UE maychange its SCell timing reference during operation, and may use one ormore SCell PRACH resources during its operation. In an exampleimplementation, a UE uses one SCell timing reference and one SCell PRACHat a given time, and multiple parallel and simultaneous PRACH operationsby a UE may not be allowed.

Assignment of cells to pTAG and sTAG are UE specific. A UE may have itsown pTAG and sTAG configuration depending on, for example, coveragearea, repeater connection, UE capability, coverage quality, and/or thelike. A UE may have a different reference timing SCell in the sTAG.Timing reference SCell may be different for different UEs, and a timingreference cell may or may not have PRACH resources in the uplink. Forexample, UE1 and UE2 may be configured with an sTAG including SCell 1and SCell 2. SCell 1 may be the timing reference for UE1, and SCell 2may be the timing reference for UE2. PRACH for SCell 1 and SCell 2 maybe communicated to the UE.

RACH configuration may be cell-specific and may be related to the cellcoverage and design parameters. SCells and PCell may have differentcoverage areas. PCell may support contention free and contention basedrandom access process, and an SCell may support contention free randomaccess process. PRACH configuration parameters for SCell and PCell maybe different. SCell PRACH configuration parameters are a subset of PCellconfiguration parameters, and all PCell PRACH configuration parametersmay not be needed for an SCell. A new field using some of the existingIEs may be introduced for PRACH configuration for an SCell in the sTAG.

Parameters related to contention based random access process may not beneeded in SCell PRACH configuration. The RACH-ConfigDedicated which isrelated to contention based random access process may not be needed forPRACH configuration for an SCell. The parameters powerRampingParameters,and preambleTransMax may be needed for a PRACH configuration for anSCell. prach-ConfigInfo may include: prach-ConfigIndex, highSpeedFlag,zeroCorrelationZoneConfig, prach-FreqOffset. The parameters in the IEPRACH-Config may be needed for an SCell to support RA procedure. Thesame RAR window configuration IE may be employed for SCell(s) and PCell.It may be convenient for eNB to use the same IE as the RAR window ofSCell and PCell random access process, since Msg2 transmission for SCelland PCell is scheduled together in eNB scheduler on the PCell RAR andemploy RAR-CRNTI. RAR window parameter of the PCell may be used for allpreamble transmissions on PCell and SCell(s).

FIG. 12 is an example flow diagram illustrating signaling mechanism toconfigure a plurality of cells and a plurality of cell groups as per anaspect of an embodiment of the present invention. According to some ofthe various embodiments a base station may be configured to communicateto wireless devices employing a plurality of cells. The wirelessdevice(s) may be compatible with LTE release 11 or above and support theconfiguration of multiple cell groups.

According to some of the various embodiments, the base station maytransmit control message(s) to a wireless device in a plurality ofwireless devices at 1200.

According to some of the various embodiments, the control message(s) maybe configured to cause in the wireless device configuration of a primarycell and a plurality of secondary cells in the plurality of cells. Thecontrol message(s) may be configured to cause in the wireless deviceassignment of each of the plurality of secondary cells to a cell groupin a plurality of cell groups. The plurality of cell groups may comprisea primary cell group and a secondary cell group. The primary cell groupmay comprise a first subset of the plurality of cells. The first subsetmay comprise the primary cell. Uplink transmissions by the wirelessdevice in the primary cell group may employ a first synchronizationsignal transmitted on the primary cell. The secondary cell group maycomprise a second subset of the plurality of secondary cells. The secondsubset may comprise a reference secondary cell. Uplink transmissions inthe secondary cell group may employ a second synchronization signal onthe reference secondary cell as a secondary timing reference. Theprimary cell group may comprise second secondary cell(s).

According to some of the various embodiments, the control message(s) maycomprise a plurality of common parameters having the same value forwireless devices in the plurality of wireless devices. The plurality ofcommon parameters may comprise the following parameters for each of atleast one first secondary cell in the plurality of secondary cells: aplurality of random access resource parameters; and a plurality of powercontrol parameters for random access preamble transmission. In oneembodiment all the cells in the at least one first secondary cell are insTAGs. In another embodiment, one or more of the SCells in the at leastone first secondary cell may be in a pTAG, but base station may beconfigured not to initiate a random access process on the PRACH of thoseSCells in pTAG.

According to some of the various embodiments, the base station maytransmit a control command to the wireless device at 1202. The controlcommand may be configurable to cause transmission of a first randomaccess preamble on a secondary cell (being one of the at least one firstsecondary cell) in the secondary cell group. The control command may betransmitted on a cell employed for scheduling uplink resources for theone of the first secondary cell(s) that is in the second subset.

The control command may be unconfigurable to cause transmission of asecond random access preamble on any secondary cell in the primary cellgroup. A PDDCH order (control command) is configured not to triggertransmission of random access preamble on an SCell of the pTAG.According to some of the various embodiments, the base station maytransmit a control command configured to cause the wireless device totransmit a third random access preamble to acquire uplink timing for theprimary cell group. The control command may be configurable: to betransmitted on a downlink of only the primary cell; and to causetransmission of the third random access preamble on an uplink of onlythe primary cell.

The transmission power of the first random access preamble may becalculated employing the plurality of power control parameters. Therandom access preamble may be received on uplink random access resourcesidentified by: a plurality of random access resource parameters; and thecontrol command. The control command may comprise a mask index; and arandom access preamble identifier.

According to some of the various embodiments, the base station maytransmit a random access response on the primary cell at 1204. Therandom access response may comprise a timing advance command for thesecondary cell group.

According to some of the various embodiments, the second secondarycell(s) in the primary cell group may not be configured with randomaccess resources. Each of the first secondary cell(s) in the secondarycell group may be configured with a random access resource.

According to some of the various embodiments, the base station maycomprise communication interface(s), processor(s), and memory. Thememory may store instructions. The processor(s) may execute theinstructions to cause actions described herein.

According to some of the various embodiments, the base station may beconfigured to communicate with the wireless device employing a pluralityof cells. A control message may be transmitted by the base station to awireless device at 1200. The control message(s) may cause in thewireless device, configuration of a primary cell and a plurality ofsecondary cells in the plurality of cells. The control message(s) maycause in the wireless device, assignment of each of the plurality ofsecondary cells to a cell group in a plurality of cell groups. Theplurality of cell groups may comprise: a primary cell group; and asecondary cell group. The primary cell group may comprise a first subsetof the plurality of cells. The first subset may comprise a primary cell.The secondary cell group may comprise a second subset of the pluralityof secondary cells. The control message(s) may comprise a plurality ofcommon parameters. The plurality of common parameters may comprise thefollowing parameters for each of at least one first secondary cell inthe plurality of secondary cells: a plurality of random access resourceparameters; and a plurality of power control parameters for randomaccess preamble transmission. In an example implementation, the controlmessage(s) may not comprise any random access resource parameter for anysecondary cell in the primary cell group.

According to some of the various embodiments, the base station maytransmit a control command to the wireless device at 1202. The controlcommand may be configurable to cause transmission of a first randomaccess preamble on a secondary cell in the secondary cell group. Thecontrol command may be unconfigurable to cause transmission of a secondrandom access preamble on any secondary cell in the primary cell group.

The random access preamble may be received on uplink random accessresources identified by: a plurality of random access resourceparameters; and the control command.

According to some of the various embodiments, the base station maytransmit a random access response on the primary cell at 1204. Therandom access response may comprise a timing advance command for thesecondary cell group. The random access response may comprise a timingadvance command. The timing advance command may comprise a timeadjustment value. The timing advance command may be configured to causesubstantial alignment of reception timing of the uplink signals inframes and subframes of the secondary cell group at the base station.

FIG. 13 is an example flow diagram illustrating a signaling mechanism toconfigure a plurality cells and a plurality of cell groups as per anaspect of an embodiment of the present invention.

According to some of the various embodiments, control message(s) from abase station may be received by a wireless device at 1300. The basestation may be configured to communicate with the wireless deviceemploying a plurality of cells. The control message(s) may cause in thewireless device, configuration of a primary cell and a plurality ofsecondary cells in the plurality of cells. The control message(s) maycause in the wireless device, assignment of each of the plurality ofsecondary cells to a cell group in a plurality of cell groups. Theplurality of cell groups may comprise a primary cell group and secondarycell group(s). The primary cell group may comprise a first subset of theplurality of cells. The first subset may comprise a primary cell. Thesecondary cell group comprising a second subset of the plurality ofsecondary cells. The control message(s) may comprise a plurality ofcommon parameters. The plurality of common parameters may comprise thefollowing parameters for each of at least one first secondary cell inthe plurality of secondary cells: a plurality of random access resourceparameters; and a plurality of power control parameters for randomaccess preamble transmission.

The control message(s) may be configured to further cause in thewireless device configuration of a time alignment timer for each of theplurality of cell groups. The time alignment timer may start or restartin response to the wireless device receiving a timing advance command toadjust uplink transmission timing of a commanded cell group in theplurality of cell groups at 1304. In an example implementation, thecontrol message(s) may not comprise any random access resourceparameters for any secondary cell in the primary cell group.

According to some of the various embodiments, a control command may bereceived from the base station at 1302. The control command may be:configurable to cause transmission of a first random access preamble ona secondary cell in the secondary cell group; and unconfigurable tocause transmission of a second random access preamble on any secondarycell in the primary cell group.

The wireless device may transmit the first random access preamble to thebase station on random access resources identified by the plurality ofrandom access resource parameters. In an sTAG, transmission timing ofthe random access preamble may be determined, at least in part,employing a second synchronization signal on an activated cell in thesecondary cell group. The transmission power of the first random accesspreamble may be calculated employing the plurality of power controlparameters.

According to some of the various aspects of embodiments, a UE may selectone active SCell DL in a secondary TAG as the DL timing reference cellfor the secondary TAG. This may reduce signalling overhead or complexityof implementation and/or increase efficiency. For a UE, an sTAG may haveone timing reference cell at a given time. In an example embodiment, theactive SCell with the highest signal quality may be selected as thetiming reference SCell by the UE. In another example embodiment, DLtiming reference cell for an sTAG may be the SCell DL SIB2-linked withthe SCell UL where RACH was performed. For preamble transmission, theSIB2 linked DL of the cell which the preamble is sent may be used as DLtiming reference. In an example embodiment, UE may autonomously select adownlink carrier in an active cell in the sTAG as the reference SCell.When TA command is received in RAR or MAC CE, the UE may apply the TAvalue to current UL timing of the corresponding TAG.

One timing reference SCell may be employed in an sTAG, the timingalignment value in RAR (random access response) or TAC (time alignmentcommand) may be applied to all active SCell(s) in the same sTAG. Thus,the UE may select the most suitable SCell for timing reference dependingon different circumstances. For example, the SCell which has a bettersignal quality may be selected as timing reference cell, since bettersignal quality may provide a more reliable performance and thus reducethe need of re-configuring the timing reference cell. Channel quality ofan SCell in an sTAG may be considered for initial SCell timing referenceand for reselecting timing reference cell. UE may change the timingreference when it is necessary.

In an example embodiment, the SCell served as the timing reference cellin sTAG may be deactivated in some cases. For a UE, eNB may keep a stateof an SCell as active or inactive. In a UE, when an SCell is inactive,the UE may switch off some parts of the receiver and/or transmittercorresponding to the SCell. This act may reduce battery powerconsumption in the UE. In another example embodiment, the referenceSCell in an sTAG may be released by the serving eNB. The timingreference cell may be changed to another active SCell in the sTAG formaintaining UL timing alignment for SCells in the same sTAG. Change oftiming reference cell in an sTAG may be supported. The reference cellmay also be changed for other reasons such as coverage quality, PRACHfailure, Reference SCell release, subscriber mobility, a combination ofthe above, and/or the like. These scenarios may apply to cases wheretime alignment is running. If the time alignment is not running and thesTAG is not time aligned, then there is no uplink synchronization and UEmay not use any reference SCell for uplink synchronization. In anexample embodiment, the UE may autonomously change the timing referenceSCell to another active SCell in the sTAG without informing the servingbase station. The UE may not inform the base station about a change inthe reference SCell, this process avoids additional signaling from a UEto the eNB and may increase radio resource efficiency. This processoptimizes reference cell selection by the UE so that the UE can select asuitable SCell as the reference, without adding complexity in thenetwork and without introducing additional signaling overhead.

According to some of the various aspects of embodiments, UE mayautonomously select another reference SCell when the reference SCellbecomes deactivated. Since the timing reference is used to derive the ULtransmission timing at the UE, there is a need for the UE to select adownlink SCell as the timing reference. The UE may autonomously reselectanother activated SCell in the sTAG as the reference when needed. Timingreference for uplink transmission on SCell may be reselected to the DLtiming of any activated SCell of the same sTAG when needed. Anyactivated SCell in the sTAG may be chosen by the UE autonomously as thetiming reference for this sTAG. For example, initially downlink SCell inwhich RA is transmitted may be used as a timing reference and then theUE may use another SCell as the timing reference, when the referenceSCell needs to be changed.

According to some of the various aspects of embodiments, if the UE isconfigured with one or more SCells, the network may activate anddeactivate the configured SCells associated with a wireless device (UE).The PCell is always activated when UE is in RRC-Connected mode. Thenetwork may activate and deactivate the SCell(s) by sending theActivation/Deactivation MAC control element. Furthermore, a UE and eNBmay maintain an SCellDeactivationTimer timer per configured SCell andmay deactivate the associated SCell upon its expiry.sCellDeactivationTimer may be configured by RRC. The same initial timervalue may apply to instances of the sCellDeactivationTimer for SCells.The configured SCells may be initially deactivated upon addition and/orafter a handover. With the current sCellDeactivationTimer, SCell may bedeactivated during the PRACH process. Transmission of uplink preamble ona deactivated SCell may increase battery power consumption and UEcomplexity. If preamble is transmitted on a deactivated SCell, UE mayneed to turn on processing related to uplink transmission of the SCell.UE may not transmit data on a deactivated SCell and transmission ofpreamble may require special processing in the UE and may complicate UEimplementation. To address this issue, if the SCell is deactivatedduring an ongoing RA process on the SCell, for example because SCelldeactivation timer expires, the ongoing random access process on theSCell may be aborted. When an SCell is deactivated, the UE may stop alluplink transmissions (for the SCell) including uplink preamble. UE maynot transmit any uplink preamble when the SCell is deactivated. eNB mayavoid or reduce the probability of such a scenario, by keeping thecorresponding SCell activated during random access process. For example,eNB can explicitly activate the SCell before the random access processstarts. An eNB may initiate a random access process when there is enoughtime for performing the entire random access process. UE may start therandom access process on an activated SCell. But if the SCelldeactivation timer (of the SCell that is used for preamble transmission)expires during the random access process, the UE may deactivate theSCell and may abort the random access process and may not transmit apreamble in the uplink. This process may prevent a situation in whichthe UE may send uplink signals on a deactivated SCell. If an SCell in aUE is deactivated after a preamble transmission on the SCell and beforereceiving a random access response corresponding to the preambletransmission, the UE may abort the random access process. A randomaccess process on an SCell is initiated in a UE when the UE received aPDCCH order to transmit a preamble on the SCell. The random accessprocess is considered successfully completed when the UE successfullydecodes a corresponding RAR. If the SCell is deactivated after therandom access process is initiated and before the random access processis completed, then the UE may abort the random access process.

According to some of the various aspects of embodiments,sCellDeactivationTimer may be maintained in a way to reduce SCelldeactivation during the RA process. The UE may for a TTI and for aconfigured SCell, if the UE receives an Activation/Deactivation MACcontrol element in this TTI activating the SCell, the UE may in the TTIaccording to a predefined timing activate the SCell and start or restartthe sCellDeactivationTimer associated with the SCell. Activating anSCell may imply applying normal SCell operation including: SRStransmissions on the SCell (if the SCell is in sync), CQI/PMI/RI/PTIreporting for the SCell, PDCCH monitoring on the SCell, PDCCH monitoringfor the SCell. If the UE receives an Activation/Deactivation MAC controlelement in this TTI deactivating the SCell, or if thesCellDeactivationTimer associated with the activated SCell expires inthis TTI, in the TTI according to a predefined timing: deactivate theSCell, stop the sCellDeactivationTimer associated with the SCell, flushall HARQ buffers associated with the SCell.

If PDCCH on the activated SCell indicates an uplink grant or downlinkassignment, or if PDCCH on the Serving Cell scheduling the activatedSCell indicates an uplink grant or a downlink assignment for theactivated SCell, the UE may restart the sCellDeactivationTimerassociated with the SCell. If the SCell is deactivated, the UE may: nottransmit SRS on the SCell, not report CQI/PMI/RI/PTI for the SCell, nottransmit on UL-SCH on the SCell, not monitor the PDCCH on the SCell, notmonitor the PDCCH for the SCell, and/or not to transmit uplink preambleon the SCell.

In an example embodiment, an SCell deactivation timer of the SCell maybe restarted when the UE receives a PDCCH order to transmit uplinkpreamble on the SCell. The SCell deactivation timer of the Cell carryingPDCCH order may also be restarted in cross carrier schedulingconfiguration. In an example implementation, an SCell deactivation timerof the SCell may be restarted when the UE transmits a random accesspreamble on the uplink the SCell.

According to some of the various aspects of embodiments, the randomaccess procedure may be initiated by a PDCCH order or by the MACsublayer itself. Random access procedure on an SCell may be initiated bya PDCCH order. If a UE receives a PDCCH transmission consistent with aPDCCH order masked with its C-RNTI (radio network temporary identifier),and for a specific serving cell, the UE may initiate a random accessprocedure on this serving cell. For random access on the PCell a PDCCHorder or RRC optionally indicate the ra-PreambleIndex and thera-PRACH-MaskIndex; and for random access on an SCell, the PDCCH orderindicates the ra-PreambleIndex with a value different from zero and thera-PRACH-MaskIndex. For the pTAG preamble transmission on PRACH andreception of a PDCCH order may only be supported for PCell.

According to some of the various aspects of embodiments, the proceduremay use some of the following information: a) the available set of PRACHresources for the transmission of the random access preamble,prach-ConfigIndex., b) for PCell, the groups of random access preamblesand/or the set of available random access preambles in each group, c)for PCell, the preambles that are contained in random access preamblesgroup A and Random Access Preambles group B are calculated, d) the RAresponse window size ra-ResponseWindowSize, e) the power-ramping factorpowerRampingStep, f) the maximum number of preamble transmissionpreambleTransMax, g) the initial preamble powerpreambleInitialReceivedTargetPower, h) the preamble format based offsetDELTA_PREAMBLE, i) for PCell, the maximum number of Msg3 HARQtransmissions maxHARQ-Msg3Tx, j) for PCell, the Contention ResolutionTimer mac-ContentionResolutionTimer. These parameters may be updatedfrom upper layers before each Random Access procedure is initiated.

According to some of the various aspects of embodiments, the RandomAccess procedure may be performed as follows: Flush the Msg3 buffer; setthe PREAMBLE_TRANSMISSION_COUNTER to 1; set the backoff parameter valuein the UE to 0 ms; for the RN (relay node), suspend any RN subframeconfiguration; proceed to the selection of the Random Access Resource.There may be one Random Access procedure ongoing at any point in time.If the UE receives a request for a new Random Access procedure whileanother is already ongoing, it may be up to UE implementation whether tocontinue with the ongoing procedure or start with the new procedure.

According to some of the various aspects of embodiments, the RandomAccess Resource selection procedure may be performed as follows. Ifra-PreambleIndex (Random Access Preamble) and ra-PRACH-MaskIndex (PRACHMask Index) have been explicitly signalled and ra-PreambleIndex is notzero, then the Random Access Preamble and the PRACH Mask Index may bethose explicitly signalled. Otherwise, the Random Access Preamble may beselected by the UE.

The UE may determine the next available subframe containing PRACHpermitted by the restrictions given by the prach-ConfigIndex, the PRACHMask Index and physical layer timing requirements (a UE may take intoaccount the possible occurrence of measurement gaps when determining thenext available PRACH subframe). If the transmission mode is TDD and thePRACH Mask Index is equal to zero, then if ra-PreambleIndex wasexplicitly signalled and it was not 0 (i.e., not selected by MAC), thenrandomly select, with equal probability, one PRACH from the PRACHsavailable in the determined subframe. Else, the UE may randomly select,with equal probability, one PRACH from the PRACHs available in thedetermined subframe and the next two consecutive subframes. If thetransmission mode is not TDD or the PRACH Mask Index is not equal tozero, a UE may determine a PRACH within the determined subframe inaccordance with the requirements of the PRACH Mask Index. Then the UEmay proceed to the transmission of the Random Access Preamble.

PRACH mask index values may range for example from 0 to 16. PRACH maskindex value may determine the allowed PRACH resource index that may beused for transmission. For example, PRACH mask index 0 may mean that allPRACH resource indeces are allowed; or PRACH mask index 1 may mean thatPRACH resource index 0 may be used. PRACH mask index may have differentmeaning in TDD and FDD systems.

The random-access procedure may be performed by UE settingPREAMBLE_RECEIVED_TARGET_POWER topreambleinitialReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_TRANSMISSION_COUNTER−1)*powerRampingStep.The UE may instruct the physical layer to transmit a preamble using theselected PRACH, corresponding RA-RNTI, preamble index andPREAMBLE_RECEIVED_TARGET_POWER.

According to some of the various aspects of embodiments, once the randomaccess preamble is transmitted and regardless of the possible occurrenceof a measurement gap, the UE may monitor the PDCCH of the PCell forrandom access response(s) identified by the RA-RNTI (random access radionetwork identifier) a specific RA-RNTI defined below, in the randomaccess response (RAR) window which may start at the subframe thatcontains the end of the preamble transmission plus three subframes andhas length ra-ResponseWindowSize subframes. The specific RA-RNTIassociated with the PRACH in which the Random Access Preamble istransmitted, is computed as: RA-RNTI=1+t_id+10*f_id. Where t_id is theindex of the first subframe of the specified PRACH (0≦t_id<10), and f_idis the index of the specified PRACH within that subframe, in ascendingorder of frequency domain (0≦f_id≦6). The UE may stop monitoring forRAR(s) after successful reception of a RAR containing random accesspreamble identifiers that matches the transmitted random accesspreamble.

According to some of the various aspects of embodiments, if a downlinkassignment for this TTI (transmission time interval) has been receivedon the PDCCH for the RA-RNTI and the received TB (transport block) issuccessfully decoded, the UE may regardless of the possible occurrenceof a measurement gap: if the RAR contains a backoff indicator (BI)subheader, set the backoff parameter value in the UE employing the BIfield of the backoff indicator subheader, else, set the backoffparameter value in the UE to zero ms. If the RAR contains a randomaccess preamble identifier corresponding to the transmitted randomaccess preamble, the UE may consider this RAR reception successful andapply the following actions for the serving cell where the random accesspreamble was transmitted: process the received riming advance commandfor the cell group in which the preamble was transmitted, indicate thepreambleInitialReceivedTargetPower and the amount of power rampingapplied to the latest preamble transmission to lower layers (i.e.,(PREAMBLE_TRANSMISSION_COUNTER−1)*powerRampingStep); process thereceived uplink grant value and indicate it to the lower layers; theuplink grant is applicable to uplink of the cell in which the preamblewas transmitted. If ra-PreambleIndex was explicitly signalled and it wasnot zero (e.g., not selected by MAC), consider the random accessprocedure successfully completed. Otherwise, if the Random AccessPreamble was selected by UE MAC, set the Temporary C-RNTI to the valuereceived in the RAR message. When an uplink transmission is required,e.g., for contention resolution, the eNB may not provide a grant smallerthan 56 bits in the Random Access Response.

According to some of the various aspects of embodiments, if no RAR isreceived within the RAR window, or if none of all received RAR containsa random access preamble identifier corresponding to the transmittedrandom access preamble, the random access response reception mayconsidered not successful. If RAR is not received, UE may incrementPREAMBLE_TRANSMISSION_COUNTER by 1. IfPREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1 and random accesspreamble is transmitted on the PCell, then UE may indicate a randomaccess problem to upper layers (RRC). This may result in radio linkfailure. If PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1 and therandom access preamble is transmitted on an SCell, then UE may considerthe random access procedure unsuccessfully completed. UE may stay in RRCconnected mode and keep the RRC connection active eventhough a randomaccess procedure unsuccessfully completed on a secondary TAG. Accordingto some of the various aspects of embodiments, at completion of therandom access procedure, the UE may discard explicitly signalledra-PreambleIndex and ra-PRACH-MaskIndex, if any; and flush the HARQbuffer used for transmission of the MAC PDU in the Msg3 buffer. Inaddition, the RN may resume the suspended RN subframe configuration, ifany.

According to some of the various aspects of embodiments, The UE may havea configurable timer timeAlignmentTimer per TAG. The timeAlignmentTimeris used to control how long the UE considers the Serving Cells belongingto the associated TAG to be uplink time aligned (in-sync). When a TimingAdvance Command MAC control element is received, the UE may apply theriming advance command for the indicated TAG, and start or restart thetimeAlignmentTimer associated with the indicated TAG. When a timingadvance command is received in a RAR message for a serving cellbelonging to a TAG and if the random access preamble was not selected byUE MAC, the UE may apply the timing advance command for this TAG, andmay start or restart the timeAlignmentTimer associated with this TAG.When a timeAlignmentTimer associated with the pTAG expires, the UE may:flush all HARQ buffers for all serving cells; notify RRC to releasePUCCH/SRS for all serving cells; clear any configured downlinkassignments and uplink grants; and consider all runningtimeAlignmentTimers as expired. When a timeAlignmentTimer associatedwith an sTAG expires, then for all Serving Cells belonging to this TAG,the UE may flush all HARQ buffers; and notify RRC to release SRS. The UEmay not perform any uplink transmission on a serving Cell except therandom access preamble transmission when the timeAlignmentTimerassociated with the TAG to which this serving cell belongs is notrunning. When the timeAlignmentTimer associated with the pTAG is notrunning, the UE may not perform any uplink transmission on any servingcell except the random access preamble transmission on the PCell. A UEstores or maintains N_TA (current timing advance value of an sTAG) uponexpiry of associated timeAlignmentTimer. The UE may apply a receivedtiming advance command MAC control element and starts associatedtimeAlignmentTimer. Transmission of the uplink radio frame number i fromthe UE may start (N_(TA)+N_(TA offset))×T_(s) seconds before the startof the corresponding downlink radio frame at the UE, where0≦N_(TA)≦20512. In an example implementation, N_(TA offset)=0 for framestructure type 1 (FDD) and N_(TA offset)=624 for frame structure type 2(TDD).

According to some of the various aspects of embodiments, upon receptionof a timing advance command for a TAG containing the primary cell, theUE may adjust uplink transmission timing for PUCCH/PUSCH/SRS of theprimary cell based on the received timing advance command. The ULtransmission timing for PUSCH/SRS of a secondary cell may be the same asthe primary cell if the secondary cell and the primary cell belong tothe same TAG. Upon reception of a timing advance command for a TAG notcontaining the primary cell, the UE may adjust uplink transmissiontiming for PUSCH/SRS of secondary cells in the TAG based on the receivedtiming advance command where the UL transmission timing for PUSCH/SRS isthe same for all the secondary cells in the TAG.

The timing advance command for a TAG may indicates the change of theuplink timing relative to the current uplink timing for the TAG asmultiples of 16 Ts (Ts: sampling time unit). The start timing of therandom access preamble may obtained employing a downlink synchronizationtime in the same TAG. In case of random access response, an 11-bittiming advance command, TA, for a TAG may indicate NTA values by indexvalues of TA=0, 1, 2, . . . , 1282, where an amount of the timealignment for the TAG may be given by NTA=TA×16. In other cases, a 6-bittiming advance command, TA, for a TAG may indicate adjustment of thecurrent NTA value, NTA,old, to the new NTA value, NTA,new, by indexvalues of TA=0, 1, 2, . . . , 63, where NTA,new=NTA,old+(TA−31)×16.Here, adjustment of NTA value by a positive or a negative amountindicates advancing or delaying the uplink transmission timing for theTAG by a given amount respectively. For a timing advance commandreceived on subframe n, the corresponding adjustment of the uplinktransmission timing may apply from the beginning of subframe n+6. Forserving cells in the same TAG, when the UE's uplink PUCCH/PUSCH/SRStransmissions in subframe n and subframe n+1 are overlapped due to thetiming adjustment, the UE may complete transmission of subframe n andnot transmit the overlapped part of subframe n+1. If the receiveddownlink timing changes and is not compensated or is only partlycompensated by the uplink timing adjustment without timing advancecommand, the UE may change NTA accordingly.

Downlink frames and subframes of downlink carriers are time aligned (bythe base station) in carrier aggregation and multiple TAG configuration.Time alignment errors may be tolerated to some extend. For example, forintra-band contiguous carrier aggregation, time alignment error may notexceed 130 ns. In another example, for intra-band non-contiguous carrieraggregation, time alignment error may not exceed 260 ns. In anotherexample, for inter-band carrier aggregation, time alignment error maynot exceed 1.3 μs.

The UE may have capability to follow the frame timing change of theconnected base station. The uplink frame transmission may take place(N_(TA)+N_(TA offset))×T_(s) before the reception of the first detectedpath (in time) of the corresponding downlink frame from the referencecell. The UE may be configured with a pTAG containing the PCell. ThepTAG may also contain one or more SCells, if configured. The UE may alsobe configured with one or more sTAGs, in which case the pTAG may containone PCell and the sTAG may contain at least one SCell with configureduplink. In pTAG, UE may use the PCell as the reference cell for derivingthe UE transmit timing for cells in the pTAG. The UE may employ asynchronization signal on the reference cell to drive downlink timing.When a UE is configured with an sTAG, the UE may use an activated SCellfrom the sTAG for deriving the UE transmit timing for cell in the sTAG.

In at least one of the various embodiments, uplink physical channel(s)may correspond to a set of resource elements carrying informationoriginating from higher layers. The following example uplink physicalchannel(s) may be defined for uplink: a) Physical Uplink Shared Channel(PUSCH), b) Physical Uplink Control Channel (PUCCH), c) Physical RandomAccess Channel (PRACH), and/or the like. Uplink physical signal(s) maybe used by the physical layer and may not carry information originatingfrom higher layers. For example, reference signal(s) may be consideredas uplink physical signal(s). Transmitted signal(s) in slot(s) may bedescribed by one or several resource grids including, for example,subcarriers and SC-FDMA or OFDMA symbols. Antenna port(s) may be definedsuch that the channel over which symbol(s) on antenna port(s) may beconveyed and/or inferred from the channel over which other symbol(s) onthe same antenna port(s) is/are conveyed. There may be one resource gridper antenna port. The antenna port(s) used for transmission of physicalchannel(s) or signal(s) may depend on the number of antenna port(s)configured for the physical channel(s) or signal(s).

According to some of the various aspects of embodiments, cell search maybe the procedure by which a wireless device may acquire time andfrequency synchronization with a cell and may detect the physical layerCell ID of that cell (transmitter). An example embodiment forsynchronization signal and cell search is presented below. A cell searchmay support a scalable overall transmission bandwidth corresponding to 6resource blocks and upwards. Primary and secondary synchronizationsignals may be transmitted in the downlink and may facilitate cellsearch. For example, 504 unique physical-layer cell identities may bedefined using synchronization signals. The physical-layer cellidentities may be grouped into 168 unique physical-layer cell-identitygroups, group(s) containing three unique identities. The grouping may besuch that physical-layer cell identit(ies) is part of a physical-layercell-identity group. A physical-layer cell identity may be defined by anumber in the range of 0 to 167, representing the physical-layercell-identity group, and a number in the range of 0 to 2, representingthe physical-layer identity within the physical-layer cell-identitygroup. The synchronization signal may include a primary synchronizationsignal and a secondary synchronization signal.

According to some of the various embodiments, physical downlink controlchannel(s) may carry transport format, scheduling assignments, uplinkpower control, and other control information. PDCCH may support multipleformats. Multiple PDCCH packets may be transmitted in a subframe.According to some of the various embodiments, scheduling controlpacket(s) may be transmitted for packet(s) or group(s) of packetstransmitted in downlink shared channel(s). Scheduling control packet(s)may include information about subcarriers used for packettransmission(s). PDCCH may also provide power control commands foruplink channels. PDCCH channel(s) may carry a plurality of downlinkcontrol packets in subframe(s). Enhance PDCCH may be implemented in acell as an option to carrier control information. According to some ofthe various embodiments, PHICH may carry the hybrid-ARQ (automaticrepeat request) ACK/NACK.

Other arrangements for PCFICH, PHICH, PDCCH, enhanced PDCCH, and/orPDSCH may be supported. The configurations presented here are forexample purposes. In another example, resources PCFICH, PHICH, and/orPDCCH radio resources may be transmitted in radio resources including asubset of subcarriers and pre-defined time duration in each or some ofthe subframes. In an example, PUSCH resource(s) may start from the firstsymbol. In another example embodiment, radio resource configuration(s)for PUSCH, PUCCH, and/or PRACH (physical random access channel) may usea different configuration. For example, channels may be timemultiplexed, or time/frequency multiplexed when mapped to uplink radioresources.

According to some of the various aspects of embodiments, the physicallayer random access preamble may comprise a cyclic prefix of length Tcpand a sequence part of length Tseq. The parameter values may bepre-defined and depend on the frame structure and a random accessconfiguration. In an example embodiment, Tcp may be 0.1 msec, and Tseqmay be 0.9 msec. Higher layers may control the preamble format. Thetransmission of a random access preamble, if triggered by the MAC layer,may be restricted to certain time and frequency resources. The start ofa random access preamble may be aligned with the start of thecorresponding uplink subframe at a wireless device.

According to an example embodiment, random access preambles may begenerated from Zadoff-Chu sequences with a zero correlation zone,generated from one or several root Zadoff-Chu sequences. In anotherexample embodiment, the preambles may also be generated using otherrandom sequences such as Gold sequences. The network may configure theset of preamble sequences a wireless device may be allowed to use.According to some of the various aspects of embodiments, there may be amultitude of preambles (e.g. 64) available in cell(s). From the physicallayer perspective, the physical layer random access procedure mayinclude the transmission of random access preamble(s) and random accessresponse(s). Remaining message(s) may be scheduled for transmission by ahigher layer on the shared data channel and may not be considered partof the physical layer random access procedure. For example, a randomaccess channel may occupy 6 resource blocks in a subframe or set ofconsecutive subframes reserved for random access preamble transmissions.

According to some of the various embodiments, the following actions maybe followed for a physical random access procedure: 1) layer 1 proceduremay be triggered upon request of a preamble transmission by higherlayers; 2) a preamble index, a target preamble received power, acorresponding RA-RNTI (random access-radio network temporary identifier)and/or a PRACH resource may be indicated by higher layers as part of arequest; 3) a preamble transmission power P_PRACH may be determined; 4)a preamble sequence may be selected from the preamble sequence set usingthe preamble index; 5) a single preamble may be transmitted usingselected preamble sequence(s) with transmission power P_PRACH on theindicated PRACH resource; 6) detection of a PDCCH with the indicated RARmay be attempted during a window controlled by higher layers; and/or thelike. If detected, the corresponding downlink shared channel transportblock may be passed to higher layers. The higher layers may parsetransport block(s) and/or indicate an uplink grant to the physicallayer(s).

According to some of the various aspects of embodiments, a random accessprocedure may be initiated by a physical downlink control channel(PDCCH) order and/or by the MAC sublayer in a wireless device. If awireless device receives a PDCCH transmission consistent with a PDCCHorder masked with its radio identifier, the wireless device may initiatea random access procedure. Preamble transmission(s) on physical randomaccess channel(s) (PRACH) may be supported on a first uplink carrier andreception of a PDCCH order may be supported on a first downlink carrier.

Before a wireless device initiates transmission of a random accesspreamble, it may access one or many of the following types ofinformation: a) available set(s) of PRACH resources for the transmissionof a random access preamble; b) group(s) of random access preambles andset(s) of available random access preambles in group(s); c) randomaccess response window size(s); d) power-ramping factor(s); e) maximumnumber(s) of preamble transmission(s); f) initial preamble power; g)preamble format based offset(s); h) contention resolution timer(s);and/or the like. These parameters may be updated from upper layers ormay be received from the base station before random access procedure(s)may be initiated.

According to some of the various aspects of embodiments, a wirelessdevice may select a random access preamble using available information.The preamble may be signaled by a base station or the preamble may berandomly selected by the wireless device. The wireless device maydetermine the next available subframe containing PRACH permitted byrestrictions given by the base station and the physical layer timingrequirements for TDD or FDD. Subframe timing and the timing oftransmitting the random access preamble may be determined based, atleast in part, on synchronization signals received from the base stationand/or the information received from the base station. The wirelessdevice may proceed to the transmission of the random access preamblewhen it has determined the timing. The random access preamble may betransmitted on a second plurality of subcarriers on the first uplinkcarrier.

According to some of the various aspects of embodiments, once a randomaccess preamble is transmitted, a wireless device may monitor the PDCCHof a primary carrier for random access response(s), in a random accessresponse window. There may be a pre-known identifier in PDCCH thatidentifies a random access response. The wireless device may stopmonitoring for random access response(s) after successful reception of arandom access response containing random access preamble identifiersthat matches the transmitted random access preamble and/or a randomaccess response address to a wireless device identifier. A base stationrandom access response may include a time alignment command. Thewireless device may process the received time alignment command and mayadjust its uplink transmission timing according the time alignment valuein the command. For example, in a random access response, a timealignment command may be coded using 11 bits, where an amount of thetime alignment may be based on the value in the command. In an exampleembodiment, when an uplink transmission is required, the base stationmay provide the wireless device a grant for uplink transmission.

If no random access response is received within the random accessresponse window, and/or if none of the received random access responsescontains a random access preamble identifier corresponding to thetransmitted random access preamble, the random access response receptionmay be considered unsuccessful and the wireless device may, based on thebackoff parameter in the wireless device, select a random backoff timeand delay the subsequent random access transmission by the backoff time,and may retransmit another random access preamble.

According to some of the various aspects of embodiments, a wirelessdevice may transmit packets on an uplink carrier. Uplink packettransmission timing may be calculated in the wireless device using thetiming of synchronization signal(s) received in a downlink. Uponreception of a timing alignment command by the wireless device, thewireless device may adjust its uplink transmission timing. The timingalignment command may indicate the change of the uplink timing relativeto the current uplink timing. The uplink transmission timing for anuplink carrier may be determined using time alignment commands and/ordownlink reference signals.

According to some of the various aspects of embodiments, a timealignment command may indicate timing adjustment for transmission ofsignals on uplink carriers. For example, a time alignment command mayuse 6 bits. Adjustment of the uplink timing by a positive or a negativeamount indicates advancing or delaying the uplink transmission timing bya given amount respectively.

For a timing alignment command received on subframe n, the correspondingadjustment of the timing may be applied with some delay, for example, itmay be applied from the beginning of subframe n+6. When the wirelessdevice's uplink transmissions in subframe n and subframe n+1 areoverlapped due to the timing adjustment, the wireless device maytransmit complete subframe n and may not transmit the overlapped part ofsubframe n+1.

According to some of the various aspects of embodiments, controlmessage(s) or control packet(s) may be scheduled for transmission in aphysical downlink shared channel (PDSCH) and/or physical uplink sharedchannel PUSCH. PDSCH and PUSCH may carry control and datamessage(s)/packet(s). Control message(s) and/or packet(s) may beprocessed before transmission. For example, the control message(s)and/or packet(s) may be fragmented or multiplexed before transmission. Acontrol message in an upper layer may be processed as a data packet inthe MAC or physical layer. For example, system information block(s),radio resource control messages, and data traffic may be scheduled fortransmission in PDSCH.

According to some of the various aspects of embodiments, a wirelessdevice may be preconfigured with one or more carriers. When the wirelessdevice is configured with more than one carrier, the base station and/orwireless device may activate and/or deactivate the configured carriers.One of the carriers (the primary carrier) may always be activated. Othercarriers may be deactivated by default and/or may be activated by a basestation when needed. A base station may activate and deactivate carriersby sending an activation/deactivation MAC control element. Furthermore,the UE may maintain a carrier deactivation timer per configured carrierand deactivate the associated carrier upon its expiry. The same initialtimer value may apply to instance(s) of the carrier deactivation timer.The initial value of the timer may be configured by a network. Theconfigured carriers (unless the primary carrier) may be initiallydeactivated upon addition and after a handover.

According to some of the various aspects of embodiments, if a wirelessdevice receives an activation/deactivation MAC control elementactivating the carrier, the wireless device may activate the carrier,and/or may apply normal carrier operation including: sounding referencesignal transmissions on the carrier (if the carrier is uplink timealigned), CQI (channel quality indicator)/PMI(precoding matrixindicator)/RI(ranking indicator) reporting for the carrier, PDCCHmonitoring on the carrier, PDCCH monitoring for the carrier, start orrestart the carrier deactivation timer associated with the carrier,and/or the like. If the device receives an activation/deactivation MACcontrol element deactivating the carrier, and/or if the carrierdeactivation timer associated with the activated carrier expires, thebase station or device may deactivate the carrier, and may stop thecarrier deactivation timer associated with the carrier, and/or may flushHARQ buffers associated with the carrier.

If PDCCH on a carrier scheduling the activated carrier indicates anuplink grant or a downlink assignment for the activated carrier, thedevice may restart the carrier deactivation timer associated with thecarrier. When a carrier is deactivated, the wireless device may nottransmit SRS (sounding reference signal) for the carrier, may not reportCQI/PMI/RI for the carrier, may not transmit on UL-SCH for the carrier,may not monitor the PDCCH on the carrier, and/or may not monitor thePDCCH for the carrier.

A process to assign subcarriers to data packets may be executed by a MAClayer scheduler. The decision on assigning subcarriers to a packet maybe made based on data packet size, resources required for transmissionof data packets (number of radio resource blocks), modulation and codingassigned to data packet(s), QoS required by the data packets (i.e. QoSparameters assigned to data packet bearer), the service class of asubscriber receiving the data packet, or subscriber device capability, acombination of the above, and/or the like.

According to some of the various aspects of embodiments, packets may bereferred to service data units and/or protocols data units at Layer 1,Layer 2 and/or Layer 3 of the communications network. Layer 2 in an LTEnetwork may include three sub-layers: PDCP sub-layer, RLC sub-layer, andMAC sub-layer. A layer 2 packet may be a PDCP packet, an RLC packet or aMAC layer packet. Layer 3 in an LTE network may be Internet Protocol(IP) layer, and a layer 3 packet may be an IP data packet. Packets maybe transmitted and received via an air interface physical layer. Apacket at the physical layer may be called a transport block. Many ofthe various embodiments may be implemented at one or many differentcommunication network layers. For example, some of the actions may beexecuted by the PDCP layer and some others by the MAC layer or PHYlayer.

According to some of the various aspects of embodiments, a radio bearermay be a GBR (guaranteed bit rate) bearer and/or a non-GBR bearer. A GBRand/or guaranteed bit rate bearer may be employed for transfer ofreal-time packets, and/or a non-GBR bearer may be used for transfer ofnon-real-time packets. The non-GBR bearer may be assigned a plurality ofattributes including: a scheduling priority, an allocation and retentionpriority, a portable device aggregate maximum bit rate, and/or the like.These parameters may be used by the scheduler in scheduling non-GBRpackets. GBR bearers may be assigned attributes such as delay, jitter,packet loss parameters, and/or the like.

According to some of the various aspects of embodiments, the transmitterin the disclosed embodiments of the present invention may be a wirelessdevice (also called user equipment), a base station (also calledeNodeB), a relay node transmitter, and/or the like. The receiver in thedisclosed embodiments of the present invention may be a wireless device(also called user equipment-UE), a base station (also called eNodeB), arelay node receiver, and/or the like.

According to some of the various aspects of embodiments, the MAC layerin some wireless device(s) may report buffer size(s) of either a singleLogical Channel Group (LCG) or a group of LCGs to a base station. An LCGmay be a group of logical channels identified by an LCG ID. The mappingof logical channel(s) to LCG may be set up during radio configuration.Buffer status report(s) may be used by a MAC scheduler to assign radioresources for packet transmission from wireless device(s). HARQ and ARQprocesses may be used for packet retransmission to enhance thereliability of radio transmission and reduce the overall probability ofpacket loss.

In this specification, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” In this specification,the term “may” is to be interpreted as “may, for example,” In otherwords, the term “may” is indicative that the phrase following the term“may” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cELL1}, {cell2}, and {cell1, cell2}.

In this specification, parameters (Information elements: IEs) maycomprise one or more objects, and each of those objects may comprise oneor more other objects. For example, if parameter (IE) N comprisesparameter (IE) M, and parameter (IE) M comprises parameter (IE) K, andparameter (IE) K comprises parameter (information element) J, then, forexample, N comprises K, and N comprises J.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e hardware with a biological element) or acombination thereof, all of which are behaviorally equivalent. Forexample, modules may be implemented as a software routine written in acomputer language configured to be executed by a hardware machine (suchas C, C++, Fortran, Java, Basic, Matlab or the like) or amodeling/simulation program such as Simulink, Stateflow, GNU Octave, orLab VIEWMathScript. Additionally, it may be possible to implementmodules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. Finally, it needs to beemphasized that the above mentioned technologies are often used incombination to achieve the result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using FDD communication systems. However, one skilled in the art willrecognize that embodiments of the invention may also be implemented inTDD communication systems. The disclosed methods and systems may beimplemented in wireless or wireline systems. The features of variousembodiments presented in this invention may be combined. One or manyfeatures (method or system) of one embodiment may be implemented inother embodiments. Only a limited number of example combinations areshown to indicate to one skilled in the art the possibility of featuresthat may be combined in various embodiments to create enhancedtransmission and reception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112, paragraph 6. Claims that do not expressly include the phrase“means for” or “step for” are not to be interpreted under 35 U.S.C. 112,paragraph 6.

What is claimed is:
 1. A base station comprising: one or moreprocessors; and memory storing instructions that, when executed, causethe base station to: receive a buffer status report indicating an amountof data available for transmission in at least one uplink buffer of awireless device; transmit, to the wireless device, a control command fortransmission of a random access preamble on a secondary cell in aplurality of cells if the base station determines: based on the bufferstatus report, that radio resources of the secondary cell are requiredfor transmission of a portion of the data in addition to radio resourceson a primary cell group; and that the secondary cell requires adifferent uplink timing from currently activated and synchronized cellsof the wireless device; receive, from the wireless device, the randomaccess preamble on the secondary cell, the secondary cell being assignedto a secondary cell group, wherein transmission timing of the randomaccess preamble is derived based, at least in part, on a firstsynchronization signal transmitted by the base station on the secondarycell group; transmit, to the wireless device, a random access responsecomprising a timing advance command for the secondary cell group; andtransmit at least one control packet comprising transport formatinformation and resource allocation information for transmission of aplurality of packets of the data on the secondary cell.
 2. The basestation of claim 1, wherein the instructions further cause the basestation to transmit at least one control message comprisingconfiguration parameters of the secondary cell.
 3. The base station ofclaim 2, wherein the at least one control message comprises at least oneradio resource control message.
 4. The base station of claim 1, whereinthe control command further comprises an index identifying the secondarycell if the control command is not transmitted on a downlink carrier ofthe secondary cell.
 5. The base station of claim 1, wherein theinstructions further cause the base station to transmit an activationcommand to activate the secondary cell.
 6. The base station of claim 1,wherein: the primary cell group comprises a first subset of theplurality of cells, and uplink transmission timing in the primary cellgroup is derived employing a first cell in the primary cell group; andthe secondary cell group comprises a second subset of the plurality ofcells, and uplink transmission timing in the secondary cell group isderived employing a second cell in the secondary cell group.
 7. A methodcomprising: receiving, by a base station, a buffer status reportindicating an amount of data available for transmission in at least oneuplink buffer of a wireless device; transmitting, by the base station tothe wireless device, a control command for transmission of a randomaccess preamble on a secondary cell in a plurality of cells if the basestation determines: based on the buffer status report, that radioresources of the secondary cell are required for transmission of aportion of the data in addition to radio resources on a primary cellgroup; and that the secondary cell requires a different uplink timingfrom currently activated and synchronized cells of the wireless device;receiving, by the base station from the wireless device, the randomaccess preamble on the secondary cell, the secondary cell being assignedto a secondary cell group, wherein transmission timing of the randomaccess preamble is derived based, at least in part, on a firstsynchronization signal transmitted by the base station on the secondarycell group; transmitting, by the base station to the wireless device, arandom access response comprising a timing advance command for thesecondary cell group; and transmitting at least one control packetcomprising transport format information and resource allocationinformation for transmission of a plurality of packets of the data onthe secondary cell.
 8. The method of claim 7, wherein a cell in theplurality of cells is assigned to a plurality of cell groups, theplurality of cell groups comprising: the primary cell group; and thesecondary cell group.
 9. The method of claim 7, further comprisingtransmitting, by the base station to the wireless device, an activationcommand to activate the secondary cell.
 10. The method of claim 7,further comprising transmitting, by the base station to the wirelessdevice, at least one control message comprising configuration parametersof the secondary cell.
 11. The method of claim 7, further comprisingtransmitting, by the base station to the wireless device, at least onecontrol message comprising: configuration parameters of the secondarycell; and a first parameter for assignment of the secondary cell to thesecondary cell group.
 12. The method of claim 7, wherein the controlcommand comprises: a mask index; and an identifier of the random accesspreamble.
 13. The method of claim 7, wherein: the primary cell groupcomprises a first subset of the plurality of cells, and uplinktransmission timing in the primary cell group is derived employing afirst cell in the primary cell group; and the secondary cell groupcomprises a second subset of the plurality of cells, and uplinktransmission timing in the secondary cell group is derived employing asecond cell in the secondary cell group.
 14. A method comprising:transmitting, by a base station to a wireless device, at least onecontrol message establishing at least one radio bearer, the at least oneradio bearer enabling uplink data transmission with a guaranteed bitrate from the wireless device; transmitting, by the base station to thewireless device, a control command for transmission of a random accesspreamble on a secondary cell in a plurality of cells if the base stationdetermines: based on the guaranteed bit rate, that radio resources ofthe secondary cell are required for transmission of a portion of theuplink data in addition to radio resources on a primary cell group; andthat the secondary cell requires a first uplink timing that is differentfrom a second uplink timing of the primary cell group; receiving, by thebase station from the wireless device, the random access preamble on thesecondary cell, the secondary cell being assigned to a secondary cellgroup, wherein transmission timing of the random access preamble isderived based, at least in part, on a first synchronization signaltransmitted by the base station on the secondary cell group;transmitting, by the base station to the wireless device, a randomaccess response comprising a first timing advance command for thesecondary cell group; and transmitting at least one control packetcomprising transport format information and resource allocationinformation for transmission of a plurality of packets of the uplinkdata on the secondary cell.
 15. The method of claim 14, wherein the atleast one control message is further configured to modify a radiobearer.
 16. The method of claim 14, wherein the random access preambleis received on uplink random access resources of the secondary cell. 17.The method of claim 14, further comprising transmitting at least onecontrol message by the base station to the wireless device, the controlmessage comprising configuration parameters of the uplink random accessresources.
 18. The method of claim 17, wherein the at least one controlmessage comprises a plurality of random access resource parameters, theplurality of random access resource parameters comprising an index, afrequency offset, and a plurality of sequence parameters.
 19. The methodof claim 14, further comprising transmitting, by the base station to thewireless device, a second timing advance command to the wireless device,the second timing advance command comprising: a time adjustment value;and an index identifying the secondary cell group; and wherein the atleast one second timing advance command causes substantial alignment ofreception timing of uplink signals in frames and subframes of thesecondary cell group at the base station.
 20. The method of claim 14,wherein: the primary cell group comprises a first subset of theplurality of cells, and uplink transmission timing in the primary cellgroup is derived employing a first cell in the primary cell group; andthe secondary cell group comprises a second subset of the plurality ofcells, and uplink transmission timing in the secondary cell group isderived employing a second cell in the secondary cell group.